해법
21.16=19.6sin(x)−29.4cos(x)
해법
x=−2.80086…+2πn,x=1.62485…+2πn
+1
도
x=−160.47763…∘+360∘n,x=93.09749…∘+360∘n솔루션 단계
21.16=19.6sin(x)−29.4cos(x)
더하다 29.4cos(x) 양쪽으로19.6sin(x)=21.16+29.4cos(x)
양쪽을 제곱(19.6sin(x))2=(21.16+29.4cos(x))2
빼다 (21.16+29.4cos(x))2 양쪽에서384.16sin2(x)−447.7456−1244.208cos(x)−864.36cos2(x)=0
삼각성을 사용하여 다시 쓰기
−447.7456−1244.208cos(x)+384.16sin2(x)−864.36cos2(x)
피타고라스 정체성 사용: cos2(x)+sin2(x)=1sin2(x)=1−cos2(x)=−447.7456−1244.208cos(x)+384.16(1−cos2(x))−864.36cos2(x)
−447.7456−1244.208cos(x)+384.16(1−cos2(x))−864.36cos2(x)간소화하다 :−1248.52cos2(x)−1244.208cos(x)−63.5856
−447.7456−1244.208cos(x)+384.16(1−cos2(x))−864.36cos2(x)
384.16(1−cos2(x))확대한다:384.16−384.16cos2(x)
384.16(1−cos2(x))
분배 법칙 적용: a(b−c)=ab−aca=384.16,b=1,c=cos2(x)=384.16⋅1−384.16cos2(x)
=1⋅384.16−384.16cos2(x)
숫자를 곱하시오: 1⋅384.16=384.16=384.16−384.16cos2(x)
=−447.7456−1244.208cos(x)+384.16−384.16cos2(x)−864.36cos2(x)
−447.7456−1244.208cos(x)+384.16−384.16cos2(x)−864.36cos2(x)단순화하세요:−1248.52cos2(x)−1244.208cos(x)−63.5856
−447.7456−1244.208cos(x)+384.16−384.16cos2(x)−864.36cos2(x)
유사 요소 추가: −384.16cos2(x)−864.36cos2(x)=−1248.52cos2(x)=−447.7456−1244.208cos(x)+384.16−1248.52cos2(x)
집단적 용어=−1244.208cos(x)−1248.52cos2(x)−447.7456+384.16
숫자 더하기/ 빼기: −447.7456+384.16=−63.5856=−1248.52cos2(x)−1244.208cos(x)−63.5856
=−1248.52cos2(x)−1244.208cos(x)−63.5856
=−1248.52cos2(x)−1244.208cos(x)−63.5856
−63.5856−1244.208cos(x)−1248.52cos2(x)=0
대체로 해결
−63.5856−1244.208cos(x)−1248.52cos2(x)=0
하게: cos(x)=u−63.5856−1244.208u−1248.52u2=0
−63.5856−1244.208u−1248.52u2=0:u=−2497.041244.208+1230501.974016,u=−2497.041244.208−1230501.974016
−63.5856−1244.208u−1248.52u2=0
표준 양식으로 작성 ax2+bx+c=0−1248.52u2−1244.208u−63.5856=0
쿼드 공식으로 해결
−1248.52u2−1244.208u−63.5856=0
4차 방정식 공식:
위해서 a=−1248.52,b=−1244.208,c=−63.5856u1,2=2(−1248.52)−(−1244.208)±(−1244.208)2−4(−1248.52)(−63.5856)
u1,2=2(−1248.52)−(−1244.208)±(−1244.208)2−4(−1248.52)(−63.5856)
(−1244.208)2−4(−1248.52)(−63.5856)=1230501.974016
(−1244.208)2−4(−1248.52)(−63.5856)
규칙 적용 −(−a)=a=(−1244.208)2−4⋅1248.52⋅63.5856
지수 규칙 적용: (−a)n=an,이면 n 균등하다(−1244.208)2=1244.2082=1244.2082−4⋅63.5856⋅1248.52
숫자를 곱하시오: 4⋅1248.52⋅63.5856=317551.573248=1244.2082−317551.573248
1244.2082=1548053.547264=1548053.547264−317551.573248
숫자를 빼세요: 1548053.547264−317551.573248=1230501.974016=1230501.974016
u1,2=2(−1248.52)−(−1244.208)±1230501.974016
솔루션 분리u1=2(−1248.52)−(−1244.208)+1230501.974016,u2=2(−1248.52)−(−1244.208)−1230501.974016
u=2(−1248.52)−(−1244.208)+1230501.974016:−2497.041244.208+1230501.974016
2(−1248.52)−(−1244.208)+1230501.974016
괄호 제거: (−a)=−a,−(−a)=a=−2⋅1248.521244.208+1230501.974016
숫자를 곱하시오: 2⋅1248.52=2497.04=−2497.041244.208+1230501.974016
분수 규칙 적용: −ba=−ba=−2497.041244.208+1230501.974016
u=2(−1248.52)−(−1244.208)−1230501.974016:−2497.041244.208−1230501.974016
2(−1248.52)−(−1244.208)−1230501.974016
괄호 제거: (−a)=−a,−(−a)=a=−2⋅1248.521244.208−1230501.974016
숫자를 곱하시오: 2⋅1248.52=2497.04=−2497.041244.208−1230501.974016
분수 규칙 적용: −ba=−ba=−2497.041244.208−1230501.974016
2차 방정식의 해는 다음과 같다:u=−2497.041244.208+1230501.974016,u=−2497.041244.208−1230501.974016
뒤로 대체 u=cos(x)cos(x)=−2497.041244.208+1230501.974016,cos(x)=−2497.041244.208−1230501.974016
cos(x)=−2497.041244.208+1230501.974016,cos(x)=−2497.041244.208−1230501.974016
cos(x)=−2497.041244.208+1230501.974016:x=arccos(−2497.041244.208+1230501.974016)+2πn,x=−arccos(−2497.041244.208+1230501.974016)+2πn
cos(x)=−2497.041244.208+1230501.974016
트리거 역속성 적용
cos(x)=−2497.041244.208+1230501.974016
일반 솔루션 cos(x)=−2497.041244.208+1230501.974016cos(x)=−a⇒x=arccos(−a)+2πn,x=−arccos(−a)+2πnx=arccos(−2497.041244.208+1230501.974016)+2πn,x=−arccos(−2497.041244.208+1230501.974016)+2πn
x=arccos(−2497.041244.208+1230501.974016)+2πn,x=−arccos(−2497.041244.208+1230501.974016)+2πn
cos(x)=−2497.041244.208−1230501.974016:x=arccos(−2497.041244.208−1230501.974016)+2πn,x=−arccos(−2497.041244.208−1230501.974016)+2πn
cos(x)=−2497.041244.208−1230501.974016
트리거 역속성 적용
cos(x)=−2497.041244.208−1230501.974016
일반 솔루션 cos(x)=−2497.041244.208−1230501.974016cos(x)=−a⇒x=arccos(−a)+2πn,x=−arccos(−a)+2πnx=arccos(−2497.041244.208−1230501.974016)+2πn,x=−arccos(−2497.041244.208−1230501.974016)+2πn
x=arccos(−2497.041244.208−1230501.974016)+2πn,x=−arccos(−2497.041244.208−1230501.974016)+2πn
모든 솔루션 결합x=arccos(−2497.041244.208+1230501.974016)+2πn,x=−arccos(−2497.041244.208+1230501.974016)+2πn,x=arccos(−2497.041244.208−1230501.974016)+2πn,x=−arccos(−2497.041244.208−1230501.974016)+2πn
해법을 원래 방정식에 연결하여 검증
솔루션을 에 연결하여 확인합니다 19.6sin(x)−29.4cos(x)=21.16
방정식에 맞지 않는 것은 제거하십시오.
솔루션 확인 arccos(−2497.041244.208+1230501.974016)+2πn:거짓
arccos(−2497.041244.208+1230501.974016)+2πn
n=1끼우다 arccos(−2497.041244.208+1230501.974016)+2π1
19.6sin(x)−29.4cos(x)=21.16 위한 {\ quad}끼우다{\ quad} x=arccos(−2497.041244.208+1230501.974016)+2π119.6sin(arccos(−2497.041244.208+1230501.974016)+2π1)−29.4cos(arccos(−2497.041244.208+1230501.974016)+2π1)=21.16
다듬다34.25965…=21.16
⇒거짓
솔루션 확인 −arccos(−2497.041244.208+1230501.974016)+2πn:참
−arccos(−2497.041244.208+1230501.974016)+2πn
n=1끼우다 −arccos(−2497.041244.208+1230501.974016)+2π1
19.6sin(x)−29.4cos(x)=21.16 위한 {\ quad}끼우다{\ quad} x=−arccos(−2497.041244.208+1230501.974016)+2π119.6sin(−arccos(−2497.041244.208+1230501.974016)+2π1)−29.4cos(−arccos(−2497.041244.208+1230501.974016)+2π1)=21.16
다듬다21.16=21.16
⇒참
솔루션 확인 arccos(−2497.041244.208−1230501.974016)+2πn:참
arccos(−2497.041244.208−1230501.974016)+2πn
n=1끼우다 arccos(−2497.041244.208−1230501.974016)+2π1
19.6sin(x)−29.4cos(x)=21.16 위한 {\ quad}끼우다{\ quad} x=arccos(−2497.041244.208−1230501.974016)+2π119.6sin(arccos(−2497.041244.208−1230501.974016)+2π1)−29.4cos(arccos(−2497.041244.208−1230501.974016)+2π1)=21.16
다듬다21.16=21.16
⇒참
솔루션 확인 −arccos(−2497.041244.208−1230501.974016)+2πn:거짓
−arccos(−2497.041244.208−1230501.974016)+2πn
n=1끼우다 −arccos(−2497.041244.208−1230501.974016)+2π1
19.6sin(x)−29.4cos(x)=21.16 위한 {\ quad}끼우다{\ quad} x=−arccos(−2497.041244.208−1230501.974016)+2π119.6sin(−arccos(−2497.041244.208−1230501.974016)+2π1)−29.4cos(−arccos(−2497.041244.208−1230501.974016)+2π1)=21.16
다듬다−17.98273…=21.16
⇒거짓
x=−arccos(−2497.041244.208+1230501.974016)+2πn,x=arccos(−2497.041244.208−1230501.974016)+2πn
해를 10진수 형식으로 표시x=−2.80086…+2πn,x=1.62485…+2πn