When x=-1:

Ok that gives us a little more information.
If we implicitly differentiate with respect to t, from the very start, then we can apply our product rule, ya?

The right side is zero, derivative of a constant is zero.
Where x' is dx/dt and y' is dy/dt.
From here, plug in all the stuff you know:
y' = -3
x = -1
y = 4
and solve for x'.
Hope that helps!
Answer:
m<HGI=21°
Step-by-step explanation:
we know that
If GH bisects m<FGI then
m<FGH=m<HGI
substitute the values
(2x+1)°=(3x-9)°
solve for x
3x-2x=1+9
x=10°
The measure of angle HGI is equal to
(3x-9)° ------> substitute the value of x
3*10-9=21°
m<HGI=21°
The answer would be C.
Sin2 cot2=sin2*cos2/sin2=cos2
Which is not equal to the others.
Hope this helps:)