SOLUTION: Could I have some help figuring out this problem. Thank you. The hypotenuse of a right triagle is 4 inches long. One leg is 1 inch longer than the other. Find the length of the sho

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equation Customizable Word Problems -> SOLUTION: Could I have some help figuring out this problem. Thank you. The hypotenuse of a right triagle is 4 inches long. One leg is 1 inch longer than the other. Find the length of the sho      Log On


   



Question 190583: Could I have some help figuring out this problem. Thank you. The hypotenuse of a right triagle is 4 inches long. One leg is 1 inch longer than the other. Find the length of the shorter leg. Round to the nearest tenth.
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
Could I have some help figuring out this problem. Thank you. The hypotenuse of a right triagle is 4 inches long. One leg is 1 inch longer than the other. Find the length of the shorter leg. Round to the nearest tenth.
.
Let x = length of shorter leg
then
x+1 = length of longer leg
.
Applying Pythagorean theorem we have:
x^2 + (x+1)^2 = 4^2
x^2 + x+^2+2x+1 = 16
2x+^2+2x+1 = 16
2x+^2+2x+-15 = 0
.
Applying the quadratic equation yields two solution:
x = {2.3, -3.3}
We can toss out the negative solution leaving us with:
x = 2.3 inches
.
Details of the quadratic follows:
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 2x%5E2%2B2x%2B-15+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%282%29%5E2-4%2A2%2A-15=124.

Discriminant d=124 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-2%2B-sqrt%28+124+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%282%29%2Bsqrt%28+124+%29%29%2F2%5C2+=+2.28388218141501
x%5B2%5D+=+%28-%282%29-sqrt%28+124+%29%29%2F2%5C2+=+-3.28388218141501

Quadratic expression 2x%5E2%2B2x%2B-15 can be factored:
2x%5E2%2B2x%2B-15+=+2%28x-2.28388218141501%29%2A%28x--3.28388218141501%29
Again, the answer is: 2.28388218141501, -3.28388218141501. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+2%2Ax%5E2%2B2%2Ax%2B-15+%29