Question

If sin 3A=cos[A-26degree]where 3A is an acutenangle,find the value of A

Answer 1

sin 3A=cos(90-3A)
given,
sin 3A=cos(A-26)
⇒cos(90-3A)=cos(A-26)
⇒90-3A=A-26
⇒4A=116
⇒A=116/4
⇒A=29