yr 11 revision - questions (1 Viewer)

[watatank]

^ if the angle is >360, do you say for eg sin (360 + A) ?


~ and if it's something like sin^2(225)

.....do you take the square root of the whole thing including the angle?

if it is more than 360 think of it as the same angle as if you were adding the angle to zero.

That is to say.... sin(405) = sin (360 + 45) = sin45 = 1/rt2

and sin^2(225) = [sin(180+45)]^2
= [-sin(45)]^2 since that is a third quadrant angle
= (-1/rt2)^2
= 1/2

...hope that makes sense :wave:

 

[-pari-]

^ thanks =)