Question

if x is a positive acute angle and cos x= 3/5, find the value of sin x

Answer 1

Use the same method as before.

Answer 2

cos(x) = adjacent / hypotenuse.
So I drew a right triangle, marked one of the angles as x, used the definition of cos(x) as adjacent / hypotenuse and made the adjacent 3 and the hypotenuse 5 because cos(x) = 3/5.
Use Pythagoras theorem to find AB.
sin(x) - opposite / hypotenuse = AB / AC = ? / 5

Answer 3

5^2+3^2=25+9=34 then what I do

Answer 4

In Pythagoras theorem, hypotenuse squared = sum of the squares of the other two sides.
And hypotenuse is the side opposite the 90 degree angle.
Here AC is the hypotenuse. So AC^2 = AB^2 + BC^2
AB^2 = AC^2 - BC^2 = 5^2 - 3^2 = ?
AB = ?

Answer 5

5.83095189485

Answer 6

No. You are still going by the wrong equation you wrote. If you look at my previous reply I corrected the error. You have to subtract 3^2 from 5^2 not add.

Answer 7

Oh sorry i did not see the minus. So that mean its 14

Answer 8

AB^2 = 5^2 - 3^2 = 25 - 9 = 16
AB = 4
sin(x) = opposite / hypotenuse = AB / AC = 4 / 5

Answer 9

Thank. You

Answer 10

You are welcome.