Question

cos(90-A) =0, then sin(A+B) =​

Answer 1

$\mathbf{QUESTION\:-}\\COS(90-A)=0\\\\\mathbf{SOLUTION\:-}\\\\WE \:KNOW\:THAT\:,\: COS(90-A)=SINA\\\therefore SINA=0\\\therefore A=0^{\circ}$

$\\\therefore SIN(A+B)=SINA\times\, COSB+COSA\times\:SINB\\=0+COSA\times\:SINB\\=SINB\\\\\mathbf{HOPE\:IT\:MAY\:HELP\:YOU...}$