Enable text based alternatives for graph display and drawing entry

Try another version of this question

Consider the function ` f(x) = 1 -8 x^2 ` on the interval ` [ -5 , 8 ] `. Find the average or mean slope of the function on this interval, i.e.
` \frac ( f(8) - f(-5) )( 8 - (-5) ) = `  

By the Mean Value Theorem, we know there exists a ` c ` in the open interval ` (-5, 8) ` such that ` f'( c) ` is equal to this mean slope. For this problem, there is only one ` c ` that works. Find it.
 

Get help: