Question

$$\displaystyle\lim_{ x \rightarrow 4 } \left(9x65 \sqrt{ 6+64x } -8 \right) \times 10^{ }$$

Evaluate

$90\sqrt{262}x_{65}-80$

Differentiate w.r.t. x_65

$90 \sqrt{262} = 1456.777265061$