Question

∠A is an acute angle in a right triangle.

Given that cosA=12\13, what is the ratio for sinA?
Enter your answer in the boxes as a fraction in simplest form.

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Answer 1

5/ 13 is your answer

Answer 2

Cos A = 12/13

`sin^(2)A` =
`1 - cos^(2)A`

Plug in the value of cos A = 12/13

`sin^(2)A` =
`1 - \left ( (12)/(13) \right )^(2)`

`sin^(2)A` =
`1 - \left ( (144)/(169) \right )`

`sin^(2)A` =
`(169-144)/(169)`

`sin^(2)A` =
`(25)/(169)`

Sin A =
`\pm` (5/13)