Question

If cos (20+x)=sin60,find x

Answer 1

Answer:

x=10 degree

Step-by-step explanation:

cos(20+x)=sin(1×90-30)

cos(20+x)=cos 30

Equating

20+x=30

x=10 degree

Answer 2

cos(20+x)=sin60

take theeta=20+x

we can write cos theeta=sin(90-theeta)

sin(90-(20+x))=sin60

90-(20+x)=60

90-20-x=60

70-x=60

-x=60-70

-x=-10

x=10

apply x in question

cos(20+10)=sin60

cos30=sin60

1/2=1/2