He function f f is given by f(x)=0.1x4−0.5x3−3.3x2+7.7x−1.99 f ( x ) = 0.1 x 4 − 0.5 x 3 − 3.3 x 2 + 7.7 x − 1.99 . For how many positive values of b b does limx→bf(x)=2 lim x → b f ( x ) = 2 ?

3

Step-by-step explanation:

We are given that

We have to find the positive value of b.

Let

Using Discartes' rule of sign

There are number of sign changes are 3.

Therefore, the positive real roots are 3 or 1.

There are number of sign changes are  1 .

Therefore, negative real roots  are 1.

When negative root is 1 .Then , positive real roots are 3 because total number of roots are 4.

Hence, positive values of b=3

final answer is : )