해법
cos2(a)=5sin(a)3
해법
솔루션없음a∈R
솔루션 단계
cos2(a)=5sin(a)3
빼다 5sin(a)3 양쪽에서cos2(a)−5sin(a)3=0
cos2(a)−5sin(a)3단순화하세요:5sin(a)5cos2(a)sin(a)−3
cos2(a)−5sin(a)3
요소를 분수로 변환: cos2(a)=5sin(a)cos2(a)5sin(a)=5sin(a)cos2(a)⋅5sin(a)−5sin(a)3
분모가 같기 때문에, 분수를 합친다: ca±cb=ca±b=5sin(a)cos2(a)⋅5sin(a)−3
5sin(a)5cos2(a)sin(a)−3=0
g(x)f(x)=0⇒f(x)=05cos2(a)sin(a)−3=0
삼각성을 사용하여 다시 쓰기
−3+5cos2(a)sin(a)
피타고라스 정체성 사용: cos2(x)+sin2(x)=1cos2(x)=1−sin2(x)=−3+5(1−sin2(a))sin(a)
−3+(1−sin2(a))⋅5sin(a)=0
대체로 해결
−3+(1−sin2(a))⋅5sin(a)=0
하게: sin(a)=u−3+(1−u2)⋅5u=0
−3+(1−u2)⋅5u=0:u≈−1.22119…
−3+(1−u2)⋅5u=0
−3+(1−u2)⋅5u 확장 :−3+5u−5u3
−3+(1−u2)⋅5u
=−3+5u(1−u2)
5u(1−u2)확대한다:5u−5u3
5u(1−u2)
분배 법칙 적용: a(b−c)=ab−aca=5u,b=1,c=u2=5u⋅1−5uu2
=5⋅1⋅u−5u2u
5⋅1⋅u−5u2u단순화하세요:5u−5u3
5⋅1⋅u−5u2u
5⋅1⋅u=5u
5⋅1⋅u
숫자를 곱하시오: 5⋅1=5=5u
5u2u=5u3
5u2u
지수 규칙 적용: ab⋅ac=ab+cu2u=u2+1=5u2+1
숫자 추가: 2+1=3=5u3
=5u−5u3
=5u−5u3
=−3+5u−5u3
−3+5u−5u3=0
표준 양식으로 작성 anxn+…+a1x+a=0−5u3+5u−3=0
다음을 위한 하나의 솔루션 찾기 −5u3+5u−3=0 뉴턴-랩슨을 이용하여:u≈−1.22119…
−5u3+5u−3=0
뉴턴-랩슨 근사 정의
f(u)=−5u3+5u−3
f′(u)찾다 :−15u2+5
dud(−5u3+5u−3)
합계/차이 규칙 적용: (f±g)′=f′±g′=−dud(5u3)+dud(5u)−dud(3)
dud(5u3)=15u2
dud(5u3)
정수를 빼라: (a⋅f)′=a⋅f′=5dud(u3)
전원 규칙을 적용합니다: dxd(xa)=a⋅xa−1=5⋅3u3−1
단순화=15u2
dud(5u)=5
dud(5u)
정수를 빼라: (a⋅f)′=a⋅f′=5dudu
공통 도함수 적용: dudu=1=5⋅1
단순화=5
dud(3)=0
dud(3)
상수의 도함수: dxd(a)=0=0
=−15u2+5−0
단순화=−15u2+5
렛 u0=−1계산하다 un+1 까지 Δun+1<0.000001
u1=−1.3:Δu1=0.3
f(u0)=−5(−1)3+5(−1)−3=−3f′(u0)=−15(−1)2+5=−10u1=−1.3
Δu1=∣−1.3−(−1)∣=0.3Δu1=0.3
u2=−1.22702…:Δu2=0.07297…
f(u1)=−5(−1.3)3+5(−1.3)−3=1.485f′(u1)=−15(−1.3)2+5=−20.35u2=−1.22702…
Δu2=∣−1.22702…−(−1.3)∣=0.07297…Δu2=0.07297…
u3=−1.22123…:Δu3=0.00579…
f(u2)=−5(−1.22702…)3+5(−1.22702…)−3=0.10189…f′(u2)=−15(−1.22702…)2+5=−17.58392…u3=−1.22123…
Δu3=∣−1.22123…−(−1.22702…)∣=0.00579…Δu3=0.00579…
u4=−1.22119…:Δu4=0.00003…
f(u3)=−5(−1.22123…)3+5(−1.22123…)−3=0.00061…f′(u3)=−15(−1.22123…)2+5=−17.37112…u4=−1.22119…
Δu4=∣−1.22119…−(−1.22123…)∣=0.00003…Δu4=0.00003…
u5=−1.22119…:Δu5=1.33081E−9
f(u4)=−5(−1.22119…)3+5(−1.22119…)−3=2.31159E−8f′(u4)=−15(−1.22119…)2+5=−17.36982…u5=−1.22119…
Δu5=∣−1.22119…−(−1.22119…)∣=1.33081E−9Δu5=1.33081E−9
u≈−1.22119…
긴 나눗셈 적용:u+1.22119…−5u3+5u−3=−5u2+6.10598…u−2.45660…
−5u2+6.10598…u−2.45660…≈0
다음을 위한 하나의 솔루션 찾기 −5u2+6.10598…u−2.45660…=0 뉴턴-랩슨을 이용하여:솔루션 없음 u∈R
−5u2+6.10598…u−2.45660…=0
뉴턴-랩슨 근사 정의
f(u)=−5u2+6.10598…u−2.45660…
f′(u)찾다 :−10u+6.10598…
dud(−5u2+6.10598…u−2.45660…)
합계/차이 규칙 적용: (f±g)′=f′±g′=−dud(5u2)+dud(6.10598…u)−dud(2.45660…)
dud(5u2)=10u
dud(5u2)
정수를 빼라: (a⋅f)′=a⋅f′=5dud(u2)
전원 규칙을 적용합니다: dxd(xa)=a⋅xa−1=5⋅2u2−1
단순화=10u
dud(6.10598…u)=6.10598…
dud(6.10598…u)
정수를 빼라: (a⋅f)′=a⋅f′=6.10598…dudu
공통 도함수 적용: dudu=1=6.10598…⋅1
단순화=6.10598…
dud(2.45660…)=0
dud(2.45660…)
상수의 도함수: dxd(a)=0=0
=−10u+6.10598…−0
단순화=−10u+6.10598…
렛 u0=0계산하다 un+1 까지 Δun+1<0.000001
u1=0.40232…:Δu1=0.40232…
f(u0)=−5⋅02+6.10598…⋅0−2.45660…=−2.45660…f′(u0)=−10⋅0+6.10598…=6.10598…u1=0.40232…
Δu1=∣0.40232…−0∣=0.40232…Δu1=0.40232…
u2=0.79092…:Δu2=0.38859…
f(u1)=−5⋅0.40232…2+6.10598…⋅0.40232…−2.45660…=−0.80933…f′(u1)=−10⋅0.40232…+6.10598…=2.08270…u2=0.79092…
Δu2=∣0.79092…−0.40232…∣=0.38859…Δu2=0.38859…
u3=0.37222…:Δu3=0.41870…
f(u2)=−5⋅0.79092…2+6.10598…⋅0.79092…−2.45660…=−0.75504…f′(u2)=−10⋅0.79092…+6.10598…=−1.80328…u3=0.37222…
Δu3=∣0.37222…−0.79092…∣=0.41870…Δu3=0.41870…
u4=0.73994…:Δu4=0.36772…
f(u3)=−5⋅0.37222…2+6.10598…⋅0.37222…−2.45660…=−0.87657…f′(u3)=−10⋅0.37222…+6.10598…=2.38377…u4=0.73994…
Δu4=∣0.73994…−0.37222…∣=0.36772…Δu4=0.36772…
u5=0.21724…:Δu5=0.52270…
f(u4)=−5⋅0.73994…2+6.10598…⋅0.73994…−2.45660…=−0.67611…f′(u4)=−10⋅0.73994…+6.10598…=−1.29348…u5=0.21724…
Δu5=∣0.21724…−0.73994…∣=0.52270…Δu5=0.52270…
u6=0.56453…:Δu6=0.34729…
f(u5)=−5⋅0.21724…2+6.10598…⋅0.21724…−2.45660…=−1.36610…f′(u5)=−10⋅0.21724…+6.10598…=3.93356…u6=0.56453…
Δu6=∣0.56453…−0.21724…∣=0.34729…Δu6=0.34729…
u7=1.87375…:Δu7=1.30922…
f(u6)=−5⋅0.56453…2+6.10598…⋅0.56453…−2.45660…=−0.60306…f′(u6)=−10⋅0.56453…+6.10598…=0.46062…u7=1.87375…
Δu7=∣1.87375…−0.56453…∣=1.30922…Δu7=1.30922…
u8=1.19527…:Δu8=0.67848…
f(u7)=−5⋅1.87375…2+6.10598…⋅1.87375…−2.45660…=−8.57033…f′(u7)=−10⋅1.87375…+6.10598…=−12.63161…u8=1.19527…
Δu8=∣1.19527…−1.87375…∣=0.67848…Δu8=0.67848…
u9=0.80160…:Δu9=0.39366…
f(u8)=−5⋅1.19527…2+6.10598…⋅1.19527…−2.45660…=−2.30169…f′(u8)=−10⋅1.19527…+6.10598…=−5.84678…u9=0.80160…
Δu9=∣0.80160…−1.19527…∣=0.39366…Δu9=0.39366…
u10=0.39593…:Δu10=0.40567…
f(u9)=−5⋅0.80160…2+6.10598…⋅0.80160…−2.45660…=−0.77487…f′(u9)=−10⋅0.80160…+6.10598…=−1.91008…u10=0.39593…
Δu10=∣0.39593…−0.80160…∣=0.40567…Δu10=0.40567…
해결 방법을 찾을 수 없습니다
해결책은u≈−1.22119…
뒤로 대체 u=sin(a)sin(a)≈−1.22119…
sin(a)≈−1.22119…
sin(a)=−1.22119…:해결책 없음
sin(a)=−1.22119…
−1≤sin(x)≤1해결책없음
모든 솔루션 결합솔루션없음a∈R