f(x) = -x²+2x+15 and g(x)=-3x+k
A(-3; 0)
B(5;0)
6.1 Show that k = 15.
6.2
Determine the coordinates of D, the turning point of f.
6.3 Determine the values of x for which f is increasing.
Calculate the average gradient between points A and D.


مه
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