pi is the angle formed by dividing a straight line in two. On the unit circle the angle is (-1,0), (0,0),(1,0).
From your knowledge of the unit circle, you know that the coordinates of the angle formed with (0,0);(1,0) are the cosine and the sine. so you know cos pi, you multiply it by three to get f(pi)
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In radians or degrees?
I'll assume radians
3 * cos π
3 * -1 = -3
f(π) = -3
f(Ï)= 3cosÏ = -3 rd
pi is the angle formed by dividing a straight line in two. On the unit circle the angle is (-1,0), (0,0),(1,0).
From your knowledge of the unit circle, you know that the coordinates of the angle formed with (0,0);(1,0) are the cosine and the sine. so you know cos pi, you multiply it by three to get f(pi)
it dosn't matter
in rad or deg
cospi= -1 or cos180= -1
3*(-1)= -3