If A + B = 90^o, then express cos B in terms of simplest trigonometric ratio of A.

Find the value of

(i) (ii)

(iii) (iv)

(v) (vi)

(vii) (viii)

(ix) sin 54° – cos 36° (x)

(xi) cosec 31° – sec 59° (xii)

(xiii)

Fill up the blanks :

(i) If sin 50^o=0.7660, then cos 40^o=……

(ii) If cos 44^o = 0.7193, then sin 46^o=…..

(iii) sin 50^o+cos 40^o = 2 sin (………)

(iv) Value of is ………

If X + Y = 90^o, then express cos X in terms of simplest trigonometric ratio of Y.

If A + B = 90^o, sin A = a, sin B = b, then prove that

(a) a² + b² = 1

(b)