<p>When I graph a function and use trace, I can only put in x values and get the result. How can I put in the y values? Anyone good with Ti-89?</p>
<p>You could graph a line Y=constant and ask the calculator to find the interesection point. Or you could just type the equation into the solve() function on the home screen.</p>
<p>Example: If your equation is Y1=3x^2+2x+5 and you want to know x when y is 3, you could make Y2=3 and find the intersection. Alternatively, you could type solve(3x^2+2x+5=3,x) on the home screen. Or, if you have it already typed into Y1, you can say solve(Y1(x)=3,x)</p>
<p>Or you can use calculus and newton's method.</p>
<p>So no quick way like you can with x? Jeez..</p>
<p>dont be lazy....</p>
<p>Yeah just graph y=constant and find the intersection.</p>
<p>The solve() function is quick once you practice it and get the key strokes down.</p>
<p>if you hamster's problem, and u want to know what x is when y = 3, u cud always just look at the table, scroll to y=3 and find x</p>
<p>But that was just an example. They may not always be looking for an integer value of y so it's best to learn other methods besides just checking the table. (And I doubt somebody who thinks the other methods were too much trouble is going to want to change the delta-y and y0 settings on their table to find the same answer.)</p>