Really need the answer, please help! The polar coordinates (8, 7π/4) represent the Cartesian point
a. (4, 4)
b. (4√2, 4√2)
c. (-4√2, 4√2)
d. (4√2, -4√2)

Question

Really need the answer, please help! The polar coordinates (8, 7π/4) represent the Cartesian point 
a. (4, 4) 
b. (4√2, 4√2) 
c. (-4√2, 4√2) 
d. (4√2, -4√2)

phi · Answer

what is 7 pi/4  radians translated to degrees ?

anonymous · Answer

401.1?

phi · Answer

multiply by 180/pi

$$ \frac{7 \pi}{4} \cdot \frac{180}{\pi} $$
notice that the pi s will cancel.
multiply top times top and bottom times bottom
simplify.

anonymous · Answer

315

phi · Answer

yes 315º

next, draw x and y axes
|dw:1367590746776:dw|

if you start at the x-axis and go counter-clockwise (up and to the left) 315 degrees, where do you end up ?

remember 360º is a full circle.

straight up is 90º,  then sideways is 180º,  straight down is 270º...

anonymous · Answer

in the 4th quadrant

phi · Answer

Here is an example going 270º
|dw:1367590930515:dw|