Quick Algebra Problem

jazduck

I have an equation which I ended up with as t^2 + t = 5.1

How do I then solve for t (without just plugging it into solve on the calculator)?

Cyosis

This should be in the homework section. You can solve it by using the ABC-formula.

jazduck

Cyosis - The question is not homework so I put it in general math. The actual question i'm trying is one on the initial velocity of an object required to catch another object released a second before it over a 50m displacement. Not that hard if I make my calculator solve it, just making a mess of the algebra because I havn't done it in 8 years.

Anyway will look up the ABC rule.

Cyosis

The solution to an equation of the form is given by . To make use of this formula you will have to write as .

HallsofIvy

Alternatively, you could "complete the square".

For any number, a,

You have which will match the first two terms of that if 2at= t or a= 1/2. In that case so adding 1/4 to both sides of the equation:

Now that the left side is a "perfect square" you have and you can solve that by taking the square root of both sides (remembering that the result can be either positive or negative).