The ratio is common, so you could write:
a1 * r^4 = a^5 (you do r^4 because there are 4 times you need to multiply by the ratio to get from a1 to a5)
Plug in the values:
3 * r^4 = 48
Divide by 3:
r^4 = 16
Take the fourth root of both sides:
r = 2
The common ratio is 2.
Given:
The equation of the curve is:

To find:
The gradient (slope) of the given curve at point (2,7).
Solution:
We have,

Differentiate the given equation with respect to x.


Now we need to find the value of this derivative at (2,7).




Therefore, the gradient (slope) of the given curve at point (2,7) is 19.
Answer:
D. 
Step-by-step explanation:
We graph the points on the graph. The graph is attached.
Let us take two points (1, 14) and (15, 1), and calculate the slope
between them <em>(we choose these points because the line passing through them will be the best fit for all points) </em>

Thus we have the equation

Let us now calculate
from the point 


So the equation we get is

Let us now turn to the choices given and see which choice is closest to our equation: we see that choice D.
is the closest one, so we pick it.
Answer:
a=1.29 approx
Step-by-step explanation:

and

(f+g)(x) =

combining like terms gives you answer choice B