Solutions
Integral CalculatorDerivative CalculatorAlgebra CalculatorMatrix CalculatorMore...
Graphing
Line Graph CalculatorExponential Graph CalculatorQuadratic Graph CalculatorSin graph CalculatorMore...
Calculators
BMI CalculatorCompound Interest CalculatorPercentage CalculatorAcceleration CalculatorMore...
Geometry
Pythagorean Theorem CalculatorCircle Area CalculatorIsosceles Triangle CalculatorTriangles CalculatorMore...
Tools
NotebookGroupsCheat SheetsWorksheetsPracticeVerify
en
English
Español
Português
Français
Deutsch
Italiano
Русский
中文(简体)
한국어
日本語
Tiếng Việt
עברית
العربية
Popular Trigonometry >

tan(θ+20)tan(90-3θ)=1

  • Pre Algebra
  • Algebra
  • Pre Calculus
  • Calculus
  • Functions
  • Linear Algebra
  • Trigonometry
  • Statistics
  • Physics
  • Chemistry
  • Finance
  • Economics
  • Conversions

Solution

tan(θ+20∘)tan(90∘−3θ)=1

Solution

θ=−180∘n+10∘,θ=−80∘−180∘n
+1
Radians
θ=18π​−πn,θ=−94π​−πn
Solution steps
tan(θ+20∘)tan(90∘−3θ)=1
Rewrite using trig identities
tan(θ+20∘)tan(90∘−3θ)=1
Rewrite using trig identities
tan(90∘−3θ)
Use the basic trigonometric identity: tan(x)=cos(x)sin(x)​=cos(90∘−3θ)sin(90∘−3θ)​
Use the Angle Difference identity: sin(s−t)=sin(s)cos(t)−cos(s)sin(t)=cos(90∘−3θ)sin(90∘)cos(3θ)−cos(90∘)sin(3θ)​
Use the Angle Difference identity: cos(s−t)=cos(s)cos(t)+sin(s)sin(t)=cos(90∘)cos(3θ)+sin(90∘)sin(3θ)sin(90∘)cos(3θ)−cos(90∘)sin(3θ)​
Simplify cos(90∘)cos(3θ)+sin(90∘)sin(3θ)sin(90∘)cos(3θ)−cos(90∘)sin(3θ)​:sin(3θ)cos(3θ)​
cos(90∘)cos(3θ)+sin(90∘)sin(3θ)sin(90∘)cos(3θ)−cos(90∘)sin(3θ)​
sin(90∘)cos(3θ)−cos(90∘)sin(3θ)=cos(3θ)
sin(90∘)cos(3θ)−cos(90∘)sin(3θ)
sin(90∘)cos(3θ)=cos(3θ)
sin(90∘)cos(3θ)
Simplify sin(90∘):1
sin(90∘)
Use the following trivial identity:sin(90∘)=1
sin(x) periodicity table with 360∘n cycle:
x030∘45∘60∘90∘120∘135∘150∘​sin(x)021​22​​23​​123​​22​​21​​x180∘210∘225∘240∘270∘300∘315∘330∘​sin(x)0−21​−22​​−23​​−1−23​​−22​​−21​​​
=1
=1⋅cos(3θ)
Multiply: 1⋅cos(3θ)=cos(3θ)=cos(3θ)
cos(90∘)sin(3θ)=0
cos(90∘)sin(3θ)
Simplify cos(90∘):0
cos(90∘)
Use the following trivial identity:cos(90∘)=0
cos(x) periodicity table with 360∘n cycle:
x030∘45∘60∘90∘120∘135∘150∘​cos(x)123​​22​​21​0−21​−22​​−23​​​x180∘210∘225∘240∘270∘300∘315∘330∘​cos(x)−1−23​​−22​​−21​021​22​​23​​​​
=0
=0⋅sin(3θ)
Apply rule 0⋅a=0=0
=cos(3θ)−0
cos(3θ)−0=cos(3θ)=cos(3θ)
=cos(90∘)cos(3θ)+sin(90∘)sin(3θ)cos(3θ)​
cos(90∘)cos(3θ)+sin(90∘)sin(3θ)=sin(3θ)
cos(90∘)cos(3θ)+sin(90∘)sin(3θ)
cos(90∘)cos(3θ)=0
cos(90∘)cos(3θ)
Simplify cos(90∘):0
cos(90∘)
Use the following trivial identity:cos(90∘)=0
cos(x) periodicity table with 360∘n cycle:
x030∘45∘60∘90∘120∘135∘150∘​cos(x)123​​22​​21​0−21​−22​​−23​​​x180∘210∘225∘240∘270∘300∘315∘330∘​cos(x)−1−23​​−22​​−21​021​22​​23​​​​
=0
=0⋅cos(3θ)
Apply rule 0⋅a=0=0
sin(90∘)sin(3θ)=sin(3θ)
sin(90∘)sin(3θ)
Simplify sin(90∘):1
sin(90∘)
Use the following trivial identity:sin(90∘)=1
sin(x) periodicity table with 360∘n cycle:
x030∘45∘60∘90∘120∘135∘150∘​sin(x)021​22​​23​​123​​22​​21​​x180∘210∘225∘240∘270∘300∘315∘330∘​sin(x)0−21​−22​​−23​​−1−23​​−22​​−21​​​
=1
=1⋅sin(3θ)
Multiply: 1⋅sin(3θ)=sin(3θ)=sin(3θ)
=0+sin(3θ)
0+sin(3θ)=sin(3θ)=sin(3θ)
=sin(3θ)cos(3θ)​
=sin(3θ)cos(3θ)​
tan(θ+20∘)sin(3θ)cos(3θ)​=1
Simplify tan(θ+20∘)sin(3θ)cos(3θ)​:sin(3θ)cos(3θ)tan(θ+20∘)​
tan(θ+20∘)sin(3θ)cos(3θ)​
Multiply fractions: a⋅cb​=ca⋅b​=sin(3θ)cos(3θ)tan(θ+20∘)​
sin(3θ)cos(3θ)tan(θ+20∘)​=1
sin(3θ)cos(3θ)tan(θ+20∘)​=1
Subtract 1 from both sidessin(3θ)cos(3θ)tan(θ+20∘)​−1=0
Simplify sin(3θ)cos(3θ)tan(θ+20∘)​−1:sin(3θ)cos(3θ)tan(99θ+180∘​)−sin(3θ)​
sin(3θ)cos(3θ)tan(θ+20∘)​−1
Join θ+20∘:99θ+180∘​
θ+20∘
Convert element to fraction: θ=9θ9​=9θ⋅9​+20∘
Since the denominators are equal, combine the fractions: ca​±cb​=ca±b​=9θ⋅9+180∘​
=sin(3θ)cos(3θ)tan(99θ+180∘​)​−1
Convert element to fraction: 1=sin(3θ)1sin(3θ)​=sin(3θ)cos(3θ)tan(9θ⋅9+180∘​)​−sin(3θ)1⋅sin(3θ)​
Since the denominators are equal, combine the fractions: ca​±cb​=ca±b​=sin(3θ)cos(3θ)tan(9θ⋅9+180∘​)−1⋅sin(3θ)​
Multiply: 1⋅sin(3θ)=sin(3θ)=sin(3θ)cos(3θ)tan(99θ+180∘​)−sin(3θ)​
sin(3θ)cos(3θ)tan(99θ+180∘​)−sin(3θ)​=0
g(x)f(x)​=0⇒f(x)=0cos(3θ)tan(99θ+180∘​)−sin(3θ)=0
Express with sin, cos
−sin(3θ)+cos(3θ)tan(9180∘+9θ​)
Use the basic trigonometric identity: tan(x)=cos(x)sin(x)​=−sin(3θ)+cos(3θ)cos(9180∘+9θ​)sin(9180∘+9θ​)​
Simplify −sin(3θ)+cos(3θ)cos(9180∘+9θ​)sin(9180∘+9θ​)​:cos(9180∘+9θ​)−sin(3θ)cos(9180∘+9θ​)+sin(9180∘+9θ​)cos(3θ)​
−sin(3θ)+cos(3θ)cos(9180∘+9θ​)sin(9180∘+9θ​)​
Multiply cos(3θ)cos(9180∘+9θ​)sin(9180∘+9θ​)​:cos(9180∘+9θ​)sin(99θ+180∘​)cos(3θ)​
cos(3θ)cos(9180∘+9θ​)sin(9180∘+9θ​)​
Multiply fractions: a⋅cb​=ca⋅b​=cos(9180∘+9θ​)sin(9180∘+9θ​)cos(3θ)​
=−sin(3θ)+cos(99θ+180∘​)sin(99θ+180∘​)cos(3θ)​
Convert element to fraction: sin(3θ)=cos(9180∘+9θ​)sin(3θ)cos(9180∘+9θ​)​=−cos(9180∘+9θ​)sin(3θ)cos(9180∘+9θ​)​+cos(9180∘+9θ​)sin(9180∘+9θ​)cos(3θ)​
Since the denominators are equal, combine the fractions: ca​±cb​=ca±b​=cos(9180∘+9θ​)−sin(3θ)cos(9180∘+9θ​)+sin(9180∘+9θ​)cos(3θ)​
=cos(9180∘+9θ​)−sin(3θ)cos(9180∘+9θ​)+sin(9180∘+9θ​)cos(3θ)​
cos(9180∘+9θ​)cos(3θ)sin(9180∘+9θ​)−cos(9180∘+9θ​)sin(3θ)​=0
g(x)f(x)​=0⇒f(x)=0cos(3θ)sin(9180∘+9θ​)−cos(9180∘+9θ​)sin(3θ)=0
Rewrite using trig identities
cos(3θ)sin(9180∘+9θ​)−cos(9180∘+9θ​)sin(3θ)
Use the Angle Difference identity: sin(s)cos(t)−cos(s)sin(t)=sin(s−t)=sin(9180∘+9θ​−3θ)
sin(9180∘+9θ​−3θ)=0
General solutions for sin(9180∘+9θ​−3θ)=0
sin(x) periodicity table with 360∘n cycle:
x030∘45∘60∘90∘120∘135∘150∘​sin(x)021​22​​23​​123​​22​​21​​x180∘210∘225∘240∘270∘300∘315∘330∘​sin(x)0−21​−22​​−23​​−1−23​​−22​​−21​​​
9180∘+9θ​−3θ=0+360∘n,9180∘+9θ​−3θ=180∘+360∘n
9180∘+9θ​−3θ=0+360∘n,9180∘+9θ​−3θ=180∘+360∘n
Solve 9180∘+9θ​−3θ=0+360∘n:θ=−180∘n+10∘
9180∘+9θ​−3θ=0+360∘n
0+360∘n=360∘n9180∘+9θ​−3θ=360∘n
Multiply both sides by 9
9180∘+9θ​−3θ=360∘n
Multiply both sides by 99180∘+9θ​⋅9−3θ⋅9=360∘n⋅9
Simplify
9180∘+9θ​⋅9−3θ⋅9=360∘n⋅9
Simplify 9180∘+9θ​⋅9:180∘+9θ
9180∘+9θ​⋅9
Multiply fractions: a⋅cb​=ca⋅b​=9(180∘+9θ)⋅9​
Cancel the common factor: 9=180∘+9θ
Simplify −3θ⋅9:−27θ
−3θ⋅9
Multiply the numbers: 3⋅9=27=−27θ
Simplify 360∘n⋅9:3240∘n
360∘n⋅9
Multiply the numbers: 2⋅9=18=3240∘n
180∘+9θ−27θ=3240∘n
180∘−18θ=3240∘n
180∘−18θ=3240∘n
180∘−18θ=3240∘n
Move 180∘to the right side
180∘−18θ=3240∘n
Subtract 180∘ from both sides180∘−18θ−180∘=3240∘n−180∘
Simplify−18θ=3240∘n−180∘
−18θ=3240∘n−180∘
Divide both sides by −18
−18θ=3240∘n−180∘
Divide both sides by −18−18−18θ​=−183240∘n​−−18180∘​
Simplify
−18−18θ​=−183240∘n​−−18180∘​
Simplify −18−18θ​:θ
−18−18θ​
Apply the fraction rule: −b−a​=ba​=1818θ​
Divide the numbers: 1818​=1=θ
Simplify −183240∘n​−−18180∘​:−180∘n+10∘
−183240∘n​−−18180∘​
−183240∘n​=−180∘n
−183240∘n​
Apply the fraction rule: −ba​=−ba​=−183240∘n​
Divide the numbers: 1818​=1=−180∘n
=−180∘n−−18180∘​
Apply the fraction rule: −ba​=−ba​=−180∘n−(−10∘)
Apply rule −(−a)=a=−180∘n+10∘
θ=−180∘n+10∘
θ=−180∘n+10∘
θ=−180∘n+10∘
Solve 9180∘+9θ​−3θ=180∘+360∘n:θ=−80∘−180∘n
9180∘+9θ​−3θ=180∘+360∘n
Multiply both sides by 9
9180∘+9θ​−3θ=180∘+360∘n
Multiply both sides by 99180∘+9θ​⋅9−3θ⋅9=180∘9+360∘n⋅9
Simplify
9180∘+9θ​⋅9−3θ⋅9=180∘9+360∘n⋅9
Simplify 9180∘+9θ​⋅9:180∘+9θ
9180∘+9θ​⋅9
Multiply fractions: a⋅cb​=ca⋅b​=9(180∘+9θ)⋅9​
Cancel the common factor: 9=180∘+9θ
Simplify −3θ⋅9:−27θ
−3θ⋅9
Multiply the numbers: 3⋅9=27=−27θ
Simplify 180∘9:1620∘
180∘9
Apply the commutative law: 180∘9=1620∘1620∘
Simplify 360∘n⋅9:3240∘n
360∘n⋅9
Multiply the numbers: 2⋅9=18=3240∘n
180∘+9θ−27θ=1620∘+3240∘n
180∘−18θ=1620∘+3240∘n
180∘−18θ=1620∘+3240∘n
180∘−18θ=1620∘+3240∘n
Move 180∘to the right side
180∘−18θ=1620∘+3240∘n
Subtract 180∘ from both sides180∘−18θ−180∘=1620∘+3240∘n−180∘
Simplify−18θ=1440∘+3240∘n
−18θ=1440∘+3240∘n
Divide both sides by −18
−18θ=1440∘+3240∘n
Divide both sides by −18−18−18θ​=−181440∘​+−183240∘n​
Simplify
−18−18θ​=−181440∘​+−183240∘n​
Simplify −18−18θ​:θ
−18−18θ​
Apply the fraction rule: −b−a​=ba​=1818θ​
Divide the numbers: 1818​=1=θ
Simplify −181440∘​+−183240∘n​:−80∘−180∘n
−181440∘​+−183240∘n​
−181440∘​=−80∘
−181440∘​
Apply the fraction rule: −ba​=−ba​=−80∘
Cancel the common factor: 2=−80∘
=−80∘+−183240∘n​
−183240∘n​=−180∘n
−183240∘n​
Apply the fraction rule: −ba​=−ba​=−183240∘n​
Divide the numbers: 1818​=1=−180∘n
=−80∘−180∘n
θ=−80∘−180∘n
θ=−80∘−180∘n
θ=−80∘−180∘n
θ=−180∘n+10∘,θ=−80∘−180∘n

Graph

Sorry, your browser does not support this application
View interactive graph

Popular Examples

2csc(x)+7/(cos(x))=0csc(θ)= 13/6(tan(θ)cot(θ))/(sec^2(θ))=cot(θ)sin(y)=(sqrt(3))/29sin^2(x)+3cos(x)-7=0

Frequently Asked Questions (FAQ)

  • What is the general solution for tan(θ+20)tan(90-3θ)=1 ?

    The general solution for tan(θ+20)tan(90-3θ)=1 is θ=-180n+10,θ=-80-180n
Study ToolsAI Math SolverPopular ProblemsWorksheetsStudy GuidesPracticeCheat SheetsCalculatorsGraphing CalculatorGeometry CalculatorVerify Solution
AppsSymbolab App (Android)Graphing Calculator (Android)Practice (Android)Symbolab App (iOS)Graphing Calculator (iOS)Practice (iOS)Chrome ExtensionSymbolab Math Solver API
CompanyAbout SymbolabBlogHelp
LegalPrivacyTermsCookie PolicyCookie SettingsDo Not Sell or Share My Personal InfoCopyright, Community Guidelines, DSA & other Legal ResourcesLearneo Legal Center
Social Media
Symbolab, a Learneo, Inc. business
© Learneo, Inc. 2024