Complex numbers can be intimidating, but they become simple. Complex numbers should be put into a+b𝑖 form. Because in this all terms end in i, you should simplify it similar to if it was any other variable (like x). So it becomes -10i. Now because there is no other term al answer is -10i.
How do you find the angles of an right triangle given the length of the sides?
If you know the length of the sides of the triangle, you can find its angles by using sine. The formula is this: sin(µ)=x(length of the opposite side)/z(length of the hypotenuse or the longest side). But the formula needs to equal µ. So the formula rewritten is: µ=sin^-1(x/z). Using this formula you should easily find the angles of the triangle. Be sure to check to make sure if you calculator is in degrees or radians to label your answer accordingly.
What is a derivative?
You can think a derivative as the slope at any given time. It is how fast the graph is increasing or decreasing. If the graph is going up, the derivative is positive. If the graph is going down, the derivative is negative. If the graph is flat, then the derivative is zero.