Question

4sin(x)^2 + 1=8cos(x) Solve for x

Answer 1

\[4(\sin x)^{2}+1=8cosx\]

Answer 2

convert sin^2x to cos^2x first

Answer 3

4(sin^2x) +1 =8cosx
4(1-cos^2x) +1 =8cosx
4cos^2x +8cosx-5=0

Answer 4

thanks

Answer 5

4cos^2x +10cosx-2cosx-5=0
2cosx(2cosx+5)-1(2cosx+5)=0
(2cosx-1)(2cosx+5)=0

Answer 6

cosx <=1
hence cosx=1/2
x= 2n(pi)+- (pi/3) where n is any integer