Math destroyer test 7 # 17

[dental deezle]

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evaluate sin (510)

I thought it would be a negative 1/2 because 510-360= 150 and that is in the third quadrant where sin is negative, how does it become positive?

 

[cdp1210]

150 is in the second quadrant where sin is positive:

0-90 degrees = 1st quadrant
90-180 degrees = 2nd quadrant
180-270 degrees = 3rd quadrant
270-360 degrees = 4th quadrant

 

[dental deezle]

150 is in the second quadrant where sin is positive:

0-90 degrees = 1st quadrant
90-180 degrees = 2nd quadrant
180-270 degrees = 3rd quadrant
270-360 degrees = 4th quadrant

wow. Im so dumb I cant believe I didnt realize that.. thank you

 

[alexis2010]

Sin(510)=sin(510-360)=sin(150)=sin(180-150)=sin(30)=1/2. Since 150 is in 2nd quadrant, sin is positive.
30° is the reference angle of 150°.