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 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^(@).

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

let a=cos A+cos b-cos(A+B) and b=4sin((A)/(2))sin((B)/(2))cos((A+B)/(2)) Then a-b is

Prove by vector method that sin(A-B)=sin A cos B-cos A sin B and sin(A+B)=sin A cos B+cos A sin B