Question

cosA cosB+sinA sinB is formula
​

Answer 1

$\Large\mathtt\green{ }\huge\underline\mathtt\red{Answer : }$

= cosA cosB + sinA sinB sin2 A + cos2 A = 1, sin 2A = 2 sinA cosA cos 2A = 2 cos2 A − 1=1 − 2 sin2 A 2 sinA cosB = sin(A + B) + sin(A − B) 2 cosA sinB = sin(A + B) − sin(A − B) 2 cosA cosB = cos(A + B) + cos(A − B) 2 sinA sinB = cos(A − B) − cos(A + B).

______________________________

Answer 2

$\Huge{\texttt{{{\color{Magenta}{⛄A}}{\red{N}}{\purple{S}}{\pink{W}}{\blue{E}}{\green{R}}{\red{♡}}{\purple{࿐⛄}}{\color{pink}{:}}}}}$

cosA cosB + sinA sinB sin2 A + cos2 A = 1, sin 2A = 2 sinA cosA cos 2A = 2 cos2 A − 1=1 − 2 sin2 A 2 sinA cosB = sin(A + B) + sin(A − B) 2 cosA sinB = sin(A + B) − sin(A − B) 2 cosA cosB = cos(A + B) + cos(A − B) 2 sinA sinB = cos(A − B) − cos(A + B).

______________________________