Question

how many real roots does the equation x4+3x2+5x -7=0 has ? Justify your answer ?​

Answer 1

X could be −3,−2,−1,0,1,2,3, so there are 7 choices for x. Likewise there are 7 choices of y.

Altogether there are 7×7=49 points that fit those requirement.

Of those only following point are distance of 2 and less (2,0),(1,−1),(1,0),(1,1)(0,2),(0,1),(0,0),(0,−1),(0,−2)(−1,−1),(−1,0),(−1,1) and (−2,0)=13 points.

So probability of points =

49

13

=0.265