At a college, records show that the average persons grade point average, G, is a function of the number of hours he or she studies and does homework per week h. The grade point average can be estimated by the equation : G=0.01h^2 +0.2h+1.2

Question

To obtain a 3.2 GPA how many hours per week would the average student need to study?

P.S. It already asked for the GPA if the student studied for 0 hrs i got 1.2 and also asked for the GPA if the student studied for 3 hrs and i got 1.89.

Answer 1

3.2 = .01 h^2 + .2 h + 1.2

.01 h^2 + .2 h - 2 = 0

h^2 + 20 h - 200 = 0

h = -10+/- 10sqrt3

h = 7.32 hr

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check h = about 7.3
.01 h^2 = .53
.2 h = .15
+ 1.2
= 3.2 ok, it works