SOLUTION: The point P on the circle x^2+y^2=r^2 that is also on the terminal side of an angle ø in standard position given.Find the indicated trigometric function. (-4,-3) Find Cos Ø

Algebra ->  Trigonometry-basics -> SOLUTION: The point P on the circle x^2+y^2=r^2 that is also on the terminal side of an angle ø in standard position given.Find the indicated trigometric function. (-4,-3) Find Cos Ø      Log On


   

Question 1004190: The point P on the circle x^2+y^2=r^2 that is also on the terminal side of an angle ø in standard position given.Find the indicated trigometric function. (-4,-3) Find Cos Ø
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
cosine theta will be equal to -4/5.

the angle will be 180 - arccos(4/5) = 143.1301024 degrees.

the equivalent angle in the first quadrant is equal to 180 - 143.1301024 degrees which is equal to 36.86989765 degrees.

the triangle is a 3/4/5 triangle in the third quadrant.

it is in the third quadrant because the adjcent side on the x-axis is negative and the opposite side on the y-axis is also negative.

the hypotenuse is always positive.

the hypotenuse is 5 because 3^2 + 4^2 = 9 + 16 = 25 and sqrt(25) = 5.

this is based on pythagorus who says that a^2 + b^2 = c^2.

a diagram of your angle is shown below:

$$$

the radius of your circle is 5, and so the equation of the circle becomes x^2 + y^2 = 25.