Q48 of 268 Page 4

Evaluate the following
cos38° cos52° – sin38° sin 52°

We know that

cos θ = sin (90° - θ)

=sin (90° - 38°) sin (90° -52°) – sin 38° sin 52°

= sin 52° sin 38°– sin 38° sin 52°

Evaluate the following

sec41° sin49° + cos49° cosec 41°

Fill in the blanks

(i) sin² θ cosec² θ = ……..

(ii) 1 + tan² θ = ……

(iii) Reciprocal sin θ. cot θ = ……

(iv) 1–.......= cos²θ

(v)

(vi)

(vii) cos θ is reciprocal of .........

(viii) Reciprocal of sin θ is.........

(ix) Value of sin θ in terms of cos θ is

(x) Value of cos θ in terms of sin θ is

Evaluate the followingcos38° cos52° – sin38° sin 52°