SOLUTION: Solve for x: cos(4x)-(1/2)sin(4x)=1
Algebra.Com
Question 921917: Solve for x: cos(4x)-(1/2)sin(4x)=1
Answer by lwsshak3(11628) (Show Source): You can put this solution on YOUR website!
Solve for x: cos(4x)-(1/2)sin(4x)=1, For[0,90˚]
let u=4x
cosu-sinu/2=1
2cosu-sinu=2
2cosu-2=sinu
2(cosu-1)=sinu
square both sides
4(cos^2u-2cosu+1)=sin^2u
4cos^2u-8cosu+4=1-cos^2u
5cos^2u-8cosu+3=0
(cosu-1)(5cosu-3)=0
cosu=1
u=0=4x
x=0
or
cosu=3/5
u≈53.13˚=4x
x≈13.28˚
RELATED QUESTIONS
Proof: sin ^4x -cos^4x=2sin^2 x-1 (answered by lwsshak3)
Verify the identity:
{{{Sin(x)(1-2*Cos^2x+ Cos^4x) =... (answered by Edwin McCravy)
Sin^4x-cos^4x=1-2cos^2x (answered by Alan3354)
sin(A+B) = sin A cos B + cos A sin B
cos(A+B) =... (answered by vleith)
Solve the equation.
Sin(3x)... (answered by Fombitz)
Solve for x:... (answered by jsmallt9)
Solve the following equations for 0deg <= x <= 360deg:
(i) cos 2x cos x = sin 4x sin x... (answered by ikleyn)
Question 624957: Verify the trig identity: sin^4(x)+cos^4 (x)=3/4 + 1/4 cos(4x).
How... (answered by jsmallt9)
solve sin(x)cos(x)=(-1/2)
(answered by Alan3354)