In which quadrant does 0 lie given that sin 0< 0 and cos 0< 0

must be in the third quadrant so that and .

Step-by-step explanation:

We have to determine that in which quadrant the angle lies if and .

The horizontal axis i.e. x-axis and the vertical axis i.e. y-axis divides the coordinate plane into four zones, the zone with x and y both positive is the first quadrant and rotating about the origin in anticlockwise we will find 2nd, 3rd and 4th quadrant one by one.

In the first quadrant all the trigonometrical functions , and are positive.

In the second quadrant only   is positive.

In the third quadrant only is positive i.e. and are negative.

In the fourth quadrant only is positive.

Therefore, must be in the third quadrant so that and . (Answer)

sorry, i can't understand your question. will later if you describe more clearly!

: )

you didn't post any answer choices, so its not 100% clear what your teacher is looking for

however, log(15/7) is equivalent to log(15) - log(7)

i'm using the rule log(x/y) = log(x) - log(y)