We know that angle MKJ is comprised of angle MKL and angle LKJ. That means if we add MKL and LKJ, we should get 80 degrees, which is the measure of angle MKJ.
So, we know that our x is 15. That is not enough to tell whether KL is an angle bisector, because we have to evaluate both MKL and LKJ with x=15, so:
So we see that these two angles are actually bisectors, and the third question best describes this phenomenon.
Answer:
Step-by-step explanation:
Sometimes, it is easiest to let a calculator do the work. (See below)
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The magnitude of the tangent is less than 1, so the reference angle will be less than 45°. Then double the angle will be less than 90°, so will remain in the 4th quadrant, where the cosine is positive and the tangent is negative.
You can also use the identities ...
cos(2θ) = (1 -tan(θ)²)/(1 +tan(θ)²)
cos(2θ) = (1 -(-3/4)²)/(1 +(-3/4)²) = ((16-9)/16)/((16+9)/16)
cos(2θ) = 7/25
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tan(2θ) = 2tan(θ)/(1 -tan(θ)²) = 2(-3/4)/((16-9/16) = (-6/4)(16/7)
tan(2θ) = -24/7
