f(x) = 50x2 + 400x + c

[t2tviking]

Hi can wolframalpha or other sites be used to solve equations such at this one with a condition? And how do you solve this?

Find value of c for function f(x) = 50x² + 400x + c when the lowest value of f(x) is 30.

 

[tkhunny]

There are many facilities to solve such things. The plan is for you to think it through. What do you know of these minimum values? Is there a way to find them using the Differential Calculus? Can you find the first derivative, f'(x)? Does that help?

 

[pka]

Hi can wolframalpha or other sites be used to solve equations such at this one with a condition? And how do you solve this?

Find value of c for function f(x) = 50x² + 400x + c when the lowest value of f(x) is 30.

The minimum occurs at the vertex of an upward opening parabola. Where is \(f'(x)=0~?\)
That is the vertex. What does \(c\) equal there? HERE

 

[Steven G]

The max/min of a parabola occurs when x=-b/(2a). Note that it does not depend on c. Just compute f( -b/(2a) ) and set it equal to 30. Solve this last equation and be done.