Question

find sin A =4/5 then cos A ​

Answer 1

Answer:

3/5

Step-by-step explanation:

using triangle method

Answer 2

Answer:

$\longrightarrow \underline{\boxed{ \bf{cos}^{2} θ = \frac{3}{5} }} \red \bigstar$

Step-by-step explanation:

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We know that,

$\sf \longrightarrow sin^{2} θ + {cos}^{2} θ = 1$

$\sf \longrightarrow \bigg( { \frac{4}{5} } \bigg)^{2} + {cos}^{2} θ = 1$

$\sf \longrightarrow \frac{16}{25} + {cos}^{2} θ = 1$

$\sf \longrightarrow {cos}^{2} θ = 1 - \frac{16}{25}$

$\sf \longrightarrow {cos}^{2} θ = \frac{25 - 16}{25}$

$\sf \longrightarrow {cos}^{2} θ = \frac{9}{25}$

Taking square root

$\longrightarrow \underline{\boxed{ \bf{cos}^{2} θ = \frac{3}{5} }} \red \bigstar$

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Thank you :)