Question

tanA×tanA=3\5 so cos A=?

Answer 1

heya friend .......

here is ur answer......
-------------------------------^^^^-

From question ..

tanA×tanA=3/5

=>tan^2 A=3/5

=>tanA=√3/5

and ....as you know that ....

tanA=p/b. 【where p is perpendicular and b is base of right triangle 】

=>then. ...by using Pythagoras theorm...

h(height )=√p^2+b^2

=.>h=√(√3)3^2+(√5)^2

=>h=√3+5

=>h=√8

=>h=2√2

now,you know that...

cosA=b/h.=√5/2√2 【where h' us height p is perpendicular】

=>cosA=√5/2√2...Ans......

hope it help you.

@Rajukumar☺☺

Answer 2

tan A x tan A = 3/5
we know that
tan = p/b
cos = h/b

p= perpendicular, h = hypotenuse and b = base
here tan^a = 3/5
tan a = root 3/5

p = root 3 & b = root 5

according to pithagorus

${h}^{2} = {p}^{2} + {b}^{2} \\ {h}^{2} = { \sqrt{3} }^{2} + { \sqrt{5} }^{2} \\ h = \sqrt{8} or \: 2 \sqrt{2} \\ \cos(a) = base \div hypotenuse \\ \sqrt{5} \div \sqrt[2]{2}$
coa a = root 5/ 2 root 2