Question

what is the value of the polyno. ial 3x2+2x+5 at x=2​

Answer 1

Answer:

Find the roots of the equation and draw the graph and accordingly you can find the least value. But since graph paper is not given, it will give only rough value, in this case, it can be found.

Solution 2: It can be solved by differentiation, however it is in class 12th and hence not applicable.

Solution 3: Rearrange the polynomial : 3(x2−35x+32)=3{(x−65)2−3625+32}=3{(x−65)2−361}

The polynomial has least value at x=5/6; which is equal to −1/12 i.e. f(65)=−121.