Answer:
Step-by-step explanation:
If you're looking for what the half angle of the tangent of theta is, I'm a bit confused as to why you think the angle in the 4th quadrant, x, is relevant. But maybe you don't know it isn't and it's a "trick" to throw you off. Hmm...
Anyways, the half angle identity for tangent is

There are actually 3 identities for the tangent of a half angle, but this one works just as well as either of the others do, so I'm going with this one.
If theta is in QIII, the value of -4 goes along the x axis and the hypotenuse is 5. That makes the missing side, by Pythagorean's Theorem, -3. Filling in our formula:
which simplifies a bit to
and a bit more to

Bring up the lower fraction and flip it to divide to get
which of course simplifies to
-3. Choice A.
First is -1 and 4, second should be no solution and the third is 2 and 6
I am not 100% positive but from what I remember learning I think the answer you are looking for on the first question is C.
Answer:
Length = 49.5 unit and width = 49.5 unit
Step-by-step explanation:
Given as , Perimeter of rectangle = 198 unit
so ,as Perimeter of rectangle = 2× ( Length + width)
Or, 198 = 2 × (Length + width)
Or,
= length + width
So, length + width = 99 unit
Now to make area maximum
Length × width = maximum
Or, (99 - width ) × width = maximum
99 Width - width² = maximum Let width = W
Now differentiate both side with respect to W
D(99W - W²)
= 0 as, constant diff is 0
So, 99 - 2w = 0
Or, w = 
Or, w = 49.5 unit and L = 99- 4905 = 49.5 unit Answer
The expression to represent this would be (m-18)/k.
We first subtract the 18 beads she used in her mother's bracelet from her beginning number, m. We then divide our result by k, the number of bracelets she made for her friends.