The phase shift is the value of the angle when the variable
in the angle is zero.
The angle in the sin function in this equation is (pi X + 2).
When the variable 'X' is zero, the angle is 2 .
So the phase shift of this sin function is 2 (of whatever
the unit of the angle is ... 2 degrees, 2 radians, etc.)
Divide the sale price by the original price:
56 / 89 = 0.7
Multiply by 100:
0.7 x 100 = 70%
The sale price is 70% of the original price, so the discount would be 30% (100-70= 30)
x ≈ 59°
Work is on piece of paper, yet I don't have a phone. I'm certain that is the answer.
Plan 1 because she spends 435.88 more if she goes with plan 2