Formulae Cos(A±B), Sin(A±B)

Standard Formula sin(A+B) || sin(A–B) || cos(A+B) || cos(A–B)

Standard Formula sin(A+B) || sin(A–B) || cos(A+B) || cos(A–B)

Standard Formula sin(A+B) || sin(A–B) || cos(A+B) || cos(A–B)

Standard Formula sin(A+B) || sin(A–B) || cos(A+B) || cos(A–B)

Using the formula of sin(A-B)=sin A cos B-cos A sin B find the value of sin15^(@)

Using the formula cos (A+B) = cosA cosB -sin A sin B . find the value of sin 15^(@) .

Prove that formula cos(A-B)=cos A*cos B+sin A*sin Bwith the help of the formula sin(A+B)=sin A*cos B+cos A*sin B

If sin A=(1)/(sqrt(5)) and sin B=(1)/(sqrt(10)) ,find the values of cos A and cos B .Hence using the formula cos(A+B)=cos A cos B-sin A sin B, show that (A+B)=45^(@).

If det [[cos (A + B), - sin (A + B), cos2Bsin A, cos A, sin B-cos A, sin A, cos B]] = 0

If det [[cos (A + B), - sin (A + B), cos2Bsin A, cos A, sin B-cos A, sin A, cos B]] = 0