
Converting from rectangular coordinates to polar coordinates involves setting

. Since the left hand side matches

perfectly, the equation's rectangular coordinate form is

.
Answer:
B or either D
Step-by-step explanation:
To find the answer use multiplication. 87% as a decimal equals 0.87 (87 divided by 100). Then multiply 0.87 by 900. Your answer should be $783.
Answer:40
Step-by-step explanation:
take the numbers add substract them multiply by x
Answer:
sin(-a)= -15 /17
Step-by-step explanation:
Alright, lets remember that sin(x) is odd function, which means that
wherever you watch an expression like this: sin(-a), you can use the odd functions property, and turn it like the following
sin(-a)= - sin(a)
Now, other thing to remember: 
So, we can obtain any value for sin(x) function starting from the opposite function, cos(x), using the following:

So, if cos(a)= - 8 / 17, using the above equation we obtain the value for sin(a)

Using the odd function property, we get the following result
sin(-a)= - sin(a) = -15/17