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Find cos(−2835°) and sin(−2835°). Identify the measure of the reference angle

User Oded Niv
by
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1 Answer

1 vote

Answer:


cos(-2835^(\circ)) = (1)/(√(2))


sin(-2835^(\circ)) = (1)/(√(2))

Solution:

As per the question:

We need to find the values of:


cos(-2835^(\circ))


sin(-2835^(\circ))

Now, we know that:


cos(- \theta) = cos\theta


sin(- \theta) = - sin\theta

Also


cos(2n\pi - \theta) = cos\theta


sin(2n\pi - \theta) = - sin\theta

Now,

From the above eqn (1) and (2):


cos(-2835^(\circ)) = cos(2835^(\circ))


sin(-2835^(\circ)) = - sin(2835^(\circ))

Now the above respective values can be further calculated from eqns (3) and (4):


cos(2(8)\pi - 45^(\circ)) = cos(45^(\circ)) = (1)/(√(2))


sin(2(8)\pi - 45^(\circ)) = -(- sin(45^(\circ))) = (1)/(√(2))

where

n = 8

User Xerkus
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5.3k points