Answer:
exterior angles 1 and 3 I hope it will help you please follow me
There are three things you have to know:
- A function is convex when its second derivative

- A function is concave when it second derivative

- The derivative of a power,
, is 
So, the first derivative is

and the second derivative is

This implies that the second derivative of a parabola is constant, and of course that 2 doesn't change the sign of
.
Answer:
Layers P, Q, R, and S are the same as layers IV, V, VI and VII.
R=d/t
15/8=7/8 divided by t
so t=7/8 divided by 15/8
t=7/15
convert to minute
so 7/15*60=28 min is answer
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