What is the solution for 2cos^2(35)cos^2(55)=? with trigonometry
I know that for example sin(y) is
sin(90x) = cos(x) if 90x=y
I know that for example sin(y) is
sin(90x) = cos(x) if 90x=y
1 Answer
Feb 26, 2018
#y=2cos^2(35^@)cos^2(55^@)=1#
Explanation:
We want to evalutae
#y=2cos^2(35^@)cos^2(55^@)#
We will use the trigonometric identities

#cos^2(x)=1/2(1+cos(2x))# 
#cos(x)=cos(180x)#
Thus
Use