# Solve an equation for a specific unknown? [closed]

I have this equation:

((a * (1 - t)^2 + 2 * d * (1 - t) * t + g * t^2) - j)^2+((b * (1 - t)^2 +
2 * e * (1 - t) * t + h * t^2) - k)^2 +
((c * (1 - t)^2 + 2 * f * (1 - t) * t + i * t^2) - l)^2 == r^2


Its long and very badly writed but I count on Wolfram to simplify it. But here I have a lot of unknown while in real all variable except $$t$$ are known, I plan to use it in a video game so even right know I don't know $$a$$, $$b$$, $$c$$, ... These variable will be known at calculation.
So I want to tell Wolfram, only $$t$$ is unknown and obtain the result $$t=a+b^2...$$.

Currently I have tried solve [my equation] for $$t$$ and searched in the equation page but I didn't find my solution.

• I'm voting to close this question as off-topic because it is Wolfram Alpha specific rather than about Mathematica. – Bob Hanlon Apr 22 '19 at 11:57

This will do but generates a very large solution:

Solve[((a*(1 - t)^2 + 2*d*(1 - t)*t + g*t^2) -
j)^2 + ((b*(1 - t)^2 + 2*e*(1 - t)*t + h*t^2) -
k)^2 + ((c*(1 - t)^2 + 2*f*(1 - t)*t + i*t^2) - l)^2 == r^2, t]


In fact there are four solutions given as a list in the above result. This is to be expected from a fourth-order polynomial equation.

• Thx but it says "Standard computation time exceeded..." will the Browser toolbar use my computer and not be limited or I have to buy pro (or optimise the request but I don't know how to do that, I'm very new with this) ? – Jorropo Apr 22 '19 at 8:05
• This site is about Mathematica, not about Wolfram Alpha. I assumed you were working with Mathematica, where the above code works. – Roman Apr 22 '19 at 8:07
• Ah ok, (I was thinking Wolfram Alpha and Mathematica to be the samethings) – Jorropo Apr 22 '19 at 8:08