What is the value of cos(50)cos(20)+sin(50)sin(20) ?

The value of cos(50)cos(20)+sin(50)sin(20) is (sqrt(3))/2

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

cos(50)cos(20)+sin(50)sin(20)

cos (5 0^{\circ}) cos (2 0^{\circ}) + sin (5 0^{\circ}) sin (2 0^{\circ})

\frac{3}{2}

Solution steps

cos (5 0^{\circ}) cos (2 0^{\circ}) + sin (5 0^{\circ}) sin (2 0^{\circ})

Rewrite using trig identities:

cos (3 0^{\circ})

= cos (3 0^{\circ})

Use the following trivial identity:

cos (3 0^{\circ}) = \frac{3}{2}

= \frac{3}{2}

\frac{tan ( 4 5 ^{\circ} ) + tan ( 3 0 ^{\circ} )}{1 - tan ( 4 5 ^{\circ} ) tan ( 3 0 ^{\circ} )}

3 sin (\frac{5 π}{4})

tan (0.01)

sin (\frac{27 π}{2})

arctan (\infty) - arctan (- \infty)

What is the value of cos(50)cos(20)+sin(50)sin(20) ?
The value of cos(50)cos(20)+sin(50)sin(20) is (sqrt(3))/2