Answer:

Step by step
Remember, a reference angle is a positive acute angle that represents an angle θ of any measurement.
a)
, then its reference angle is 
b)
is in the second cuadrant, then its reference angle is 
c)
, then it is in the first cuadrant and the reference angle is
.
d)
and it is in the third cuadrant, then its reference angle is 
Let Xavier's favourite fraction be a/b, Yessie's favourite fraction = b/a and Zorro's favourite fraction = c/d,
c/d x a/b = 12/35 . . . . . . . . (1)
c/d x b/a = 15/7 . . . . . . . . (2)
(1) x (2) = c/d x a/b x c/d x b/a = 12/35 x 15/7
c^2 / d^2 = 36/49
c^2 = 36
c = 6
d^2 = 49
d = 7
Xaviers favourite fraction = 12/35 / 6/7 = 2/5
Yessies favourite fraction = 5/2
Zorro favourite fraction = 6/7
The vertex of the quadratic equation is (-5, - 28). In vertex form, y = a(x - h)2<span> + </span><span>k, (h, k) is the vertex of the equation.</span>
Giraffe = 1,000 kg
Whale = 2,000,000 kg
Whale has 2,000 times the mass.