Question

Draw the graphs of the quadratic polynomial f(x)=3-2x -x?

JEE/Engineering Exams

Maths

Solution

4.0 (1 ratings)

Let y= f(x) or, y=3 - 2x - x2 Let us list a few values of y=3 - 2x - x2 corresponding to a few values of x as follows: Ix - 4-2-10/1 2 3 4 y=3-2x-x² -12 5 3 4 3 0 5 -12 | 21 | Thus, the following points lie on the graph of polynomial y=3- 2x - x2: (-5, -12), (-4,-5),(-3,0),(-2,3), (-1,4),(0,3), (1,0), (2,-5), (3,-12) and (4, -21) Let us plot these points on a graph paper and draw a smooth free hand curve passing through these points to obtain the graph of y=3 - 2x - x2. The curve thus obtained represents a parabola, as shown in figure. TOSIN