Question

25^2cos(x+3pi/2)=(1/5)^2cos(x+pi)

Answer 1

$25^{2cos(frac{3pi}{2}+x)}=(frac{1}{5})^{2cos(pi+x)}\(5^2)^{2cos(frac{3pi}{2}+x)}=(5^2)^{-cos(pi+x)}\2cos(frac{3pi}{2}+x)+cos(pi+x)=0\2sinx-cosx=0\2sinx=cosx|:cosx\2tgx=1\tgx=frac{1}{2}to x=arctgfrac{1}{2}+pi n,nin Z$