Question

If sin 4- cos B =0, prove that A+B =90

Answer 1

Answer:

given,

sinA - cosB = 0

=> sinA = cosB

=> cos( 90 - A) = cosB

on comparing both sides,

90 -A = B

=> 90 = B + A

or,

A + B = 90°.

hence proved..

Step-by-step explanation:

FORmula used: cos( 90 - ∅) = sin∅

* some other important formula:

1. sin(90 - ∅) = cos∅

2. sec( 90 - ∅) = cosec∅

3. cosec(90 - ∅) = sec∅.

$..$

Answer 2

$\sin(A) - \cos(B) = 0$

$\sin(A) = \cos(B)$

$\cos(90 - A) = \cos(B)$

$on \: comparing \: both \: sides$

$90 - A= B$

$90 = B + A \: or \: A+B=90$