Question

if sinA=4/5 then tan2A will be??​

Answer 1

Answer:

24/7 is correct ans

Explanation:

if SinA=4/5

then Cos A=3/5 (by trigonometry identities)

now Tan 2A=Tan A + Tan A/1-Tan A.Tan A

now Tan A=Sin. A/ Cos A=4/3

so tan 2A= (4/3)×2/1-(4/3)^2

=(8/3)/ (-7/9)

= -24/7

Answer 2

Answer:

$1 - { \cos(a) }^{2} = { \sin(a) }^{2} \\ { \cos(a) }^{2} = ( \frac{ {4}^{2} }{ {5}^{2}) } - 1 \\ = \frac{16}{25} - 1 \\ = \frac{16 - 25}{25} \\ = \frac{9}{25} \\ \cos(a) = \frac{3}{5}$

$\tan(a) = \frac{ \sin(a) }{ \cos(a) } = \frac{4}{5 } \div \frac{3}{5} = \frac{4}{3}$

$2 \tan(a) = 2 \times \frac{4}{3} = \frac{8}{3}$

that's is your answer