" Evaluate: "cos6 theta-cos8 theta

Express each of the following as a product: sin4 theta+sin2 theta( ii) sin6 theta-sin2 theta( iii) cos4 theta+cos8 theta( iii) cos6 theta-cos8 theta

Find the value of (cos6 theta+6cos4 theta+15cos2 theta+10)/(cos5 theta+5cos theta+10cos theta)

Find the values of theta betwen 0^(@) and 180^(@) satisying the equation cos6 theta+cos4 theta+cos2 theta+1=0

Prove that: (cos6 theta+6cos4 theta+15cos2 theta+10)/(cos5 theta+5cos3 theta+10cos theta)=2cos theta

Find all the values of theta satisfying the equation cos 2 theta - cos 8 theta + cos 6 theta =1, such that 0 le theta le pi.

If 13 theta =pi , " prove that " cos theta cos 2theta cos3 theta cos4theta cos5 theta cos6 theta =1/2^(6)

If tan theta = 15/8 and cos theta is negative, find the value of (sin (-theta) - cos theta)/(tan(-theta) + "sec"(-theta)) .

Evaluate: int cos2 theta ln((cos theta+sin theta)/(cos theta-sin theta))d theta

If tan theta=(a)/(b) , then find the value of (sin theta)/(cos^(8)theta)+(cos theta)/(sin^(8)theta) .

Show that :((cos theta-cos3 theta)(sin8 theta+sin2 theta))/((sin5 theta-sin theta)(cos4 theta-cos6 theta))=1