" 21.If "tan theta=(a)/(b)" ,prove that "a sin2 theta+b cos2 theta=b

If tan theta =(a)/(b) prove that a sin 2theta + b cos 2theta =b

If tan theta =a/b , prove that a sin 2 theta+b cos 2 theta=b .

(i) If "tan""(x)/(2)=(m)/(n) ,prove that m sin x+n cos x=n. (ii) If "tan" theta=(a)/(b) , prove that a sin 2theta+b cos 2theta=b .

If tan theta=(a)/(b), prove that (a sin theta-b cos theta)/(a sin theta+b cos theta)=(a^(2)-b^(2))/(a^(2)+b^(2))

If tan theta=(a)/(b), show that (a sin theta-b cos theta)/(a sin theta+b cos theta)=(a^(2)-b^(2))/(a^(2)+b^(2))

If tan theta . =(b)/(a) then prove that acos 2 theta +b sin 2 theta =a

If tan theta=(a)/(b) then b cos2 theta+a sin2 theta=

If a cos theta - b sin theta = c, prove that a sin theta + b cos theta = pm sqrt(a^(2) + b^(2) - c^(2)) .

If tan theta=(a)/(b) such that (a sin theta-b cos theta)/(a sin theta+b cos theta)=(a^(2)-b^(2))/(a^(2)+b^(2))^(k) then k is ?