GeminiHeat wrote:
If x^4 + y^4 = 100, then the greatest possible value of x is between
A. 0 and 3
B. 3 and 6
C. 6 and 9
D. 9 and 12
E. 12 and 15
In order to maximize the value of x, we must minimize the value of y⁴.
Since y⁴ ≥ 0 for all values of y, the minimum value of y⁴ occurs when y = 0.
If y = 0, we get: x⁴ + 0⁴ = 100
Simplify: : x⁴ = 100
3⁴ = 81 and
4⁴ = 256
Since 100 is between 81 and 256, we know that x is between
3 and
4 Answer: B