Question

If tan=20/21 show that 1-sin+cos/1+sin+cos=3/7

Answer 1

Step-by-step explanation:

tane = 20/21 = opposite side(of)/ adjacent side(a)

hypotenuse = h = o? + a?

Let , o = 20k and a = 21k

h2 = (20k)2 + (21k)?

= 841k? =

h = 29 k

sine = o/h

= 20k/29k

=20/29

cose = a/h =

= 21k/29k = 21/29

1- sin + cos ÷ 1+ sin + cos

= {1 - 20/29 + 21/29 /1} (1+ 20/29 + 21/29}

= {29/29 - 20/29 + 21/29) - = (29/29+20/29+21/29}

= (29 - 20 + 21/29} - {29+20+21/29}

= 30/29 70/29

29 gets cancelled on both denominator and numerator.

= 30/70

= 3/7

= RHS

HOPE IT HELPS YOU!!!