Question

If tan 25= X
{tan155+Tan115}/1+Tan155Tan115=(1-x^2)/2x​

Answer 1

Step-by-step explanation:

tan155=tan(180-25) = -tan25 = -x

tan115=tan(90+25)= -cot25 = -1/tan25 = -1/x

tan155+Tan115}/1+Tan155Tan115

= (-x +(-1/x)) / (1 + (-x)(-1/x))

=((-x^2-1)/x )/ (1+1)

= -(1+x^2)/2x