Question

tan thita=-1/root 5 then find cos thita​

Answer 1

tan@ = -(1/√5)

we know , sec^2@ = (1 + tan^2@)

=> sec^2@ = 1 + (-1/5)^2

=> sec^2@ = 1 + 1/5 = (6/5)

=> sec@ = √6/√5

cos@ = 1/sec@

=> cos@ = (√5/√6)