Question

WE
8. If Sin (A + B) = 1 = cos(A-B) then
(a) A = B = 90'
(b) A =B = 0'
(c) 4 =B = 45
(d) 4 = 2B​

Answer 1

Answer:

A=B=90 degree

Step-by-step explanation:

using identity

Answer 2

Answer:

A = B = 45

Step-by-step explanation:

1. sin (A+B) = 1

sin (A+B) = 90°

so, A+B = 90°.......(1)

2. cos (A-B) = 1

cos (A-B) = 0°

so, A-B = 0°........(2)

Add equation (1) and (2)

A+B+A-B = 90°+0°

A+A = 90° [because +B and -B are cancelled]

2A = 90°

A = 90°/2

A = 45°

Substitute A = 45 in equation (1)

45°+B = 90°

B = 90°- 45°

B = 45°

Therefore,

A = 45°

B = 45°