If cot A is undefined, then A =?

A = 0°

Step-by-step explanation:

a) Terrance's speed- 12  

    Jesse's speed -8

b) Teerance ;- 4 hr 10 min ; Jesse ;- 6 hr 15 min

c)  Sandra's speed :-  

Step-by-step explanation:

Terrance runs

in an hour 6 miles

So in 1 hour he / she  runs miles

   = 12 miles.

So Terrance's speed is 12 ---(1)

Jesse's runs

In 15 minutes 2 miles

So, In 1 minute miles

So, in 60 minutes miles

                                                 = 8 miles

So, Jesse's speed is 8 ----------(2)

Terrance runs,

12 miles in 1 hour

so, 1 mile in hour

so, 50 miles in hour

= hour

=4  hour minutes

= 4 hour 10 minutes.

Jesse runs,

8 miles in 1 hour

so, 50 miles in hour

= hour

= 6 hour minutes

= 6 hour 15 minutes

Sandra runs,

in 45 minutes 8 miles

so, in 1 minute mile

so, in 60 minutes miles

= miles

So Sandra's speed is , ---------------- (3)