Math/Physics
posted by Hujinson .
Thanks in advance, these problems have been stumping me. Please include answers though, I have tried to work it out, but need answers to see where I am going wrong/where I need to go.
1. Determine all solutions for X^4+23i
2. Forces of 60 and 100 pounds have a resultant force of 125 pounds, what is the angle between the vectors?
3. Consider a truck hat weighs 5000 pounds at an incline of 20 degrees. What is the braking force required to keep the truck from rolling down the hill?
4. Two forces with a direction of 30 degrees and 60 degrees and magnitudes of 5 and 13 respectively act on a point. Find the direction and magnitude of the resultant force.

1. You have not written an equation. Algebraic expressions by themselves do not have solutions.
2. Use the law of cosines.
z^2 = x^2 + y^2 + 2xy cosZ
z is the resultant and Z is the angle between the two components.
z = 125; x = 60 and y = 100
Solve for the angle Z by getting its cosine.
3. The required braking force is the component of 5000# down the slope.
4. Add the x and y components of the two forces separately. Then get the magnitude of the resultant with the Pythagorean theorem. Get the angle from the arctangent.
Show your work if you have problems, then we can tell you where you are making mistakes. 
Alright, the first one is equal to zero.
I figured out 2,
for three I got 171 pounds of force
Im currently working on 4