Question

find the value of !!

Answer 1

Given equation is,

[cos(90°-∅)cos∅] / cot∅ - 1

we know that,

cos(90°-∅) = sin∅

sin∅cos∅/ (cos∅/sin∅) - 1

sin²∅ - 1 (:. cos∅ cancel out each other)

1- cos²∅ - 1

= - cos²∅

Hope this answer may help you

Answer 2

$\huge\star\underbrace {\mathtt\purple {A}\mathtt\purple {n}\mathtt\purple {s}\mathtt\purple {w}\mathtt\purple {e}\mathtt\purple {r}}\star\:$

[cos(90°-∅)cos∅] / cot∅ - 1

we know that,

cos(90°-∅) = sin∅

sin∅cos∅/ (cos∅/sin∅) - 1

sin²∅ - 1 (:. cos∅ cancel out each other)

1- cos²∅ - 1

= - cos²∅