Find sin2a if sina=3/5 and a is in quadrant 2

We know that,

sin²(a) + cos²(a) = 1

cos(a) =

cos(a) = 

Thus, cos(a) = +- 

We know a is in second quadrant and thus cos(a) is - because cosine is always negative in the second quadrant.

Therefore,

sin(2a) = 2*sin(a)*cos(a) = 

answer is 67%

step-by-step explanation:

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.