Question

Please I need help.Show full working out. (a) sin x cot x= cos x (b) (1 + tan theta)^2 + (1- tan theta)^2 = 2sec^2theta

Answer 1

since cot = cos/sin,
sin cot = sin * cos/sin = cos

expand the two tan expressions and recall that
sec^2 = 1 + tan^2