no! i did this right. A is the angle between the hypotenuse whose slope is 2/5 and m1.
then is used tan(90-A)= 1/tan A for m2 and and replaced m2 with -1/m2. to get two values of m1 with respect to tan A.
Then, here are two possible reasons for the result:
1. You did not take into account the absolute value. Take the negative of one of those terms. Then you will probably get 0=0.
2. You are dividing by zero somewhere. Note that in the formula for tangent, if , the denominator is zero. Perhaps that can happen elsewhere in the problem, as well.
Edit: I just calculated it out. You did not take into account the absolute value. Calculating with and ) or calculating with and and solving for each time, I get the exact same result:
yielding the possible outcomes or . These cannot BOTH be true unless .
The absolute value in this formula is used to find the tanA of the acute angle as the acute angle can be formed by the lines in two ways. But as this is a right triangle. I dont think we need to take the modulus into account.
The absolute value in this formula is used to find the tanA of the acute angle as the acute angle can be formed by the lines in two ways. But as this is a right triangle. I dont think we need to take the modulus into account.
When two lines intersect, they form four angles. Unless they are all right angles, two of them will be obtuse and two will be acute. That is why the formula you are given takes the absolute value. It cannot be ignored.