+118733 
+118733 Find all values of 
such that 
.
$$\\8t^2+10t-3\le0\\\\
graph\;\;y=8t^2+10t-3\\\\
$and see where $y\le0$$
I am going to use a graphing program but you can use the quadratic formula to find the roots and then it is a concave up parabola. (because the number in fron ot x^2 is positive)
Here is the graph
https://www.desmos.com/calculator/hm59laowni
From the graph it can be seen that the answer is [-1.5,0.25]
