At what value(s) of x does f(x) = -x^4 + 2x^2 have a relative maximum? (4 points)
1 answer:
Take the derivitive
f'(x)=-4x^3+4x
find where it equals 0
0=-4x(x^2-1)
0=-4x(x-1)(x+1)
at x=-1, 0, 1
those are critical points
put those on number line
test points between to see if positive or negative
f'(-2)=(+)
f'(-0.5)=(-)
f'(0.5)=(+)
f'(2)=(-)
see attachment
remember the max is where the slope changes from positive to negative
at -1 and 1 only
f'(x)=-4x^3+4x
find where it equals 0
0=-4x(x^2-1)
0=-4x(x-1)(x+1)
at x=-1, 0, 1
those are critical points
put those on number line
test points between to see if positive or negative
f'(-2)=(+)
f'(-0.5)=(-)
f'(0.5)=(+)
f'(2)=(-)
see attachment
remember the max is where the slope changes from positive to negative
at -1 and 1 only
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Answer:
- Elanor's standardized score is 1.19
- Gerald's standardized score is 0.72
- Elanor has higher score
Step-by-step explanation:
To compare Elanor's and Gerald's math scores, we need to standardize them and calculate their z-scores.
z score can be calculated using the formula
z= where
- X is the student's score
- M is the mean score of the exam
- s is the standard deviation of the exam
Elanor's standardized score is:
z(e) = ≈ 1.19
Gerald's standardized score is:
z(g)= ≈ 0.72
Since z(e) > z(g), Elanor has higher score