Thread: i want to explain the solution in this question

i want to explain the solution in this question ..
I worked a red line on the steps that I did not understood it

Originally Posted by r-soy

i want to explain the solution in this question ..

I worked a red line on the steps that I did not understood it

Hi r-soy,





Does that help?

Hi but from where we get

in step 2

Originally Posted by r-soy

Hi but from where we get

in step 2

Looks like it might be a mistake to me. Should be

thanks so much

ok who u can know

cos(3pi/2)=cos(270)=0
sin(3pi/2)=sin(270)= -1

from where i can get 0 and -1 ?

give me a way to finid them

Originally Posted by r-soy

ok who u can know

cos(3pi/2)=cos(270)=0
sin(3pi/2)=sin(270)= -1

from where i can get 0 and -1 ?

give me a way to finid them

On your unit circle, at an angle of 270 deg or 3pi/2, the coordinates of the intersection of the circle with the negative side of the y-axis is (0, -1). Cosine is defined as x/r, where x = x-coordinate of the circle and r = the radius.



Similarly, sine 270 is defined as y/r.



Print this image and study it: Unit Circle