Question

If theta be an acute angle and 5cosec theta is equal to 7,then evaluate sin theta+cos^2-1

Answer 1

Answer:

Step-by-step explanation:

Let, theta=a

5coseca=7

Coseca=7/5=h/p

i.e., h=7, p=5

b=√h2-p2

=√(7)2-(5)2

=√49-25

=√24

=4√6 cm

Now,

sina+cos2a-1

=p/h+(b/h)2-1

=5/7+(4√6/7)2-1

=5/7+16×6/49-1

=5/7+96/49-1

=35+96-49/49

=55/49