해법
50sec2(5x)tan(5x)=25+tan2(5x)
해법
x=50.40289…+5πn
+1
도
x=4.61683…∘+36∘n솔루션 단계
50sec2(5x)tan(5x)=25+tan2(5x)
빼다 25+tan2(5x) 양쪽에서50sec2(5x)tan(5x)−25−tan2(5x)=0
삼각성을 사용하여 다시 쓰기
−25−tan2(5x)+50sec2(5x)tan(5x)
피타고라스 정체성 사용: sec2(x)=tan2(x)+1=−25−tan2(5x)+50(tan2(5x)+1)tan(5x)
−25−tan2(5x)+(1+tan2(5x))⋅50tan(5x)=0
대체로 해결
−25−tan2(5x)+(1+tan2(5x))⋅50tan(5x)=0
하게: tan(5x)=u−25−u2+(1+u2)⋅50u=0
−25−u2+(1+u2)⋅50u=0:u≈0.42620…
−25−u2+(1+u2)⋅50u=0
−25−u2+(1+u2)⋅50u 확장 :−25−u2+50u+50u3
−25−u2+(1+u2)⋅50u
=−25−u2+50u(1+u2)
50u(1+u2)확대한다:50u+50u3
50u(1+u2)
분배 법칙 적용: a(b+c)=ab+aca=50u,b=1,c=u2=50u⋅1+50uu2
=50⋅1⋅u+50u2u
50⋅1⋅u+50u2u단순화하세요:50u+50u3
50⋅1⋅u+50u2u
50⋅1⋅u=50u
50⋅1⋅u
숫자를 곱하시오: 50⋅1=50=50u
50u2u=50u3
50u2u
지수 규칙 적용: ab⋅ac=ab+cu2u=u2+1=50u2+1
숫자 추가: 2+1=3=50u3
=50u+50u3
=50u+50u3
=−25−u2+50u+50u3
−25−u2+50u+50u3=0
표준 양식으로 작성 anxn+…+a1x+a0=050u3−u2+50u−25=0
다음을 위한 하나의 솔루션 찾기 50u3−u2+50u−25=0 뉴턴-랩슨을 이용하여:u≈0.42620…
50u3−u2+50u−25=0
뉴턴-랩슨 근사 정의
f(u)=50u3−u2+50u−25
f′(u)찾다 :150u2−2u+50
dud(50u3−u2+50u−25)
합계/차이 규칙 적용: (f±g)′=f′±g′=dud(50u3)−dud(u2)+dud(50u)−dud(25)
dud(50u3)=150u2
dud(50u3)
정수를 빼라: (a⋅f)′=a⋅f′=50dud(u3)
전원 규칙을 적용합니다: dxd(xa)=a⋅xa−1=50⋅3u3−1
단순화=150u2
dud(u2)=2u
dud(u2)
전원 규칙을 적용합니다: dxd(xa)=a⋅xa−1=2u2−1
단순화=2u
dud(50u)=50
dud(50u)
정수를 빼라: (a⋅f)′=a⋅f′=50dudu
공통 도함수 적용: dudu=1=50⋅1
단순화=50
dud(25)=0
dud(25)
상수의 도함수: dxd(a)=0=0
=150u2−2u+50−0
단순화=150u2−2u+50
렛 u0=1계산하다 un+1 까지 Δun+1<0.000001
u1=0.62626…:Δu1=0.37373…
f(u0)=50⋅13−12+50⋅1−25=74f′(u0)=150⋅12−2⋅1+50=198u1=0.62626…
Δu1=∣0.62626…−1∣=0.37373…Δu1=0.37373…
u2=0.45706…:Δu2=0.16919…
f(u1)=50⋅0.62626…3−0.62626…2+50⋅0.62626…−25=18.20208…f′(u1)=150⋅0.62626…2−2⋅0.62626…+50=107.57820…u2=0.45706…
Δu2=∣0.45706…−0.62626…∣=0.16919…Δu2=0.16919…
u3=0.42699…:Δu3=0.03007…
f(u2)=50⋅0.45706…3−0.45706…2+50⋅0.45706…−25=2.41849…f′(u2)=150⋅0.45706…2−2⋅0.45706…+50=80.42199…u3=0.42699…
Δu3=∣0.42699…−0.45706…∣=0.03007…Δu3=0.03007…
u4=0.42621…:Δu4=0.00078…
f(u3)=50⋅0.42699…3−0.42699…2+50⋅0.42699…−25=0.05973…f′(u3)=150⋅0.42699…2−2⋅0.42699…+50=76.49426…u4=0.42621…
Δu4=∣0.42621…−0.42699…∣=0.00078…Δu4=0.00078…
u5=0.42620…:Δu5=5.03019E−7
f(u4)=50⋅0.42621…3−0.42621…2+50⋅0.42621…−25=0.00003…f′(u4)=150⋅0.42621…2−2⋅0.42621…+50=76.39588…u5=0.42620…
Δu5=∣0.42620…−0.42621…∣=5.03019E−7Δu5=5.03019E−7
u≈0.42620…
긴 나눗셈 적용:u−0.42620…50u3−u2+50u−25=50u2+20.31049…u+58.65653…
50u2+20.31049…u+58.65653…≈0
다음을 위한 하나의 솔루션 찾기 50u2+20.31049…u+58.65653…=0 뉴턴-랩슨을 이용하여:솔루션 없음 u∈R
50u2+20.31049…u+58.65653…=0
뉴턴-랩슨 근사 정의
f(u)=50u2+20.31049…u+58.65653…
f′(u)찾다 :100u+20.31049…
dud(50u2+20.31049…u+58.65653…)
합계/차이 규칙 적용: (f±g)′=f′±g′=dud(50u2)+dud(20.31049…u)+dud(58.65653…)
dud(50u2)=100u
dud(50u2)
정수를 빼라: (a⋅f)′=a⋅f′=50dud(u2)
전원 규칙을 적용합니다: dxd(xa)=a⋅xa−1=50⋅2u2−1
단순화=100u
dud(20.31049…u)=20.31049…
dud(20.31049…u)
정수를 빼라: (a⋅f)′=a⋅f′=20.31049…dudu
공통 도함수 적용: dudu=1=20.31049…⋅1
단순화=20.31049…
dud(58.65653…)=0
dud(58.65653…)
상수의 도함수: dxd(a)=0=0
=100u+20.31049…+0
단순화=100u+20.31049…
렛 u0=−3계산하다 un+1 까지 Δun+1<0.000001
u1=−1.39920…:Δu1=1.60079…
f(u0)=50(−3)2+20.31049…(−3)+58.65653…=447.72504…f′(u0)=100(−3)+20.31049…=−279.68950…u1=−1.39920…
Δu1=∣−1.39920…−(−3)∣=1.60079…Δu1=1.60079…
u2=−0.32800…:Δu2=1.07120…
f(u1)=50(−1.39920…)2+20.31049…(−1.39920…)+58.65653…=128.12693…f′(u1)=100(−1.39920…)+20.31049…=−119.61018…u2=−0.32800…
Δu2=∣−0.32800…−(−1.39920…)∣=1.07120…Δu2=1.07120…
u3=4.26567…:Δu3=4.59367…
f(u2)=50(−0.32800…)2+20.31049…(−0.32800…)+58.65653…=57.37392…f′(u2)=100(−0.32800…)+20.31049…=−12.48976…u3=4.26567…
Δu3=∣4.26567…−(−0.32800…)∣=4.59367…Δu3=4.59367…
u4=1.90464…:Δu4=2.36103…
f(u3)=50⋅4.26567…2+20.31049…⋅4.26567…+58.65653…=1055.09312…f′(u3)=100⋅4.26567…+20.31049…=446.87787…u4=1.90464…
Δu4=∣1.90464…−4.26567…∣=2.36103…Δu4=2.36103…
u5=0.58226…:Δu5=1.32237…
f(u4)=50⋅1.90464…2+20.31049…⋅1.90464…+58.65653…=278.72369…f′(u4)=100⋅1.90464…+20.31049…=210.77463…u5=0.58226…
Δu5=∣0.58226…−1.90464…∣=1.32237…Δu5=1.32237…
u6=−0.53102…:Δu6=1.11328…
f(u5)=50⋅0.58226…2+20.31049…⋅0.58226…+58.65653…=87.43414…f′(u5)=100⋅0.58226…+20.31049…=78.53686…u6=−0.53102…
Δu6=∣−0.53102…−0.58226…∣=1.11328…Δu6=1.11328…
u7=1.35878…:Δu7=1.88980…
f(u6)=50(−0.53102…)2+20.31049…(−0.53102…)+58.65653…=61.97051…f′(u6)=100(−0.53102…)+20.31049…=−32.79194…u7=1.35878…
Δu7=∣1.35878…−(−0.53102…)∣=1.88980…Δu7=1.88980…
u8=0.21549…:Δu8=1.14328…
f(u7)=50⋅1.35878…2+20.31049…⋅1.35878…+58.65653…=178.56892…f′(u7)=100⋅1.35878…+20.31049…=156.18896…u8=0.21549…
Δu8=∣0.21549…−1.35878…∣=1.14328…Δu8=1.14328…
u9=−1.34577…:Δu9=1.56127…
f(u8)=50⋅0.21549…2+20.31049…⋅0.21549…+58.65653…=65.35533…f′(u8)=100⋅0.21549…+20.31049…=41.86020…u9=−1.34577…
Δu9=∣−1.34577…−0.21549…∣=1.56127…Δu9=1.56127…
u10=−0.27916…:Δu10=1.06661…
f(u9)=50(−1.34577…)2+20.31049…(−1.34577…)+58.65653…=121.87917…f′(u9)=100(−1.34577…)+20.31049…=−114.26742…u10=−0.27916…
Δu10=∣−0.27916…−(−1.34577…)∣=1.06661…Δu10=1.06661…
u11=7.19949…:Δu11=7.47865…
f(u10)=50(−0.27916…)2+20.31049…(−0.27916…)+58.65653…=56.88321…f′(u10)=100(−0.27916…)+20.31049…=−7.60607…u11=7.19949…
Δu11=∣7.19949…−(−0.27916…)∣=7.47865…Δu11=7.47865…
해결 방법을 찾을 수 없습니다
해결책은u≈0.42620…
뒤로 대체 u=tan(5x)tan(5x)≈0.42620…
tan(5x)≈0.42620…
tan(5x)=0.42620…:x=5arctan(0.42620…)+5πn
tan(5x)=0.42620…
트리거 역속성 적용
tan(5x)=0.42620…
일반 솔루션 tan(5x)=0.42620…tan(x)=a⇒x=arctan(a)+πn5x=arctan(0.42620…)+πn
5x=arctan(0.42620…)+πn
5x=arctan(0.42620…)+πn해결 :x=5arctan(0.42620…)+5πn
5x=arctan(0.42620…)+πn
양쪽을 다음으로 나눕니다 5
5x=arctan(0.42620…)+πn
양쪽을 다음으로 나눕니다 555x=5arctan(0.42620…)+5πn
단순화x=5arctan(0.42620…)+5πn
x=5arctan(0.42620…)+5πn
x=5arctan(0.42620…)+5πn
모든 솔루션 결합x=5arctan(0.42620…)+5πn
해를 10진수 형식으로 표시x=50.40289…+5πn