A shopkeeper in Jaipur sells x toys daily and his profit (in Rs) is modelled by -x^2 + 20x - 100. Setting the profit to a target T, he gets the equation x^2 - 20x + (100 + T) = 0. For the highest target T that still allows a real number of toys, what must the discriminant equal?

Question

Accepted Answer

0. At the highest reachable target the equation has exactly one (repeated) real solution for x, so the discriminant is 0. Here 400 - 4(100 + T) = 0 gives T = 0 at that boundary, but the key idea is D = 0 for the maximum case.

A shopkeeper in Jaipur sells $x$ toys daily and his profit (in Rs) is modelled by $- x^{2} + 20 x - 100$ . Setting the profit to a target $T$ , he gets the equation $x^{2} - 20 x + (100 + T) = 0$ .
For the highest target $T$ that still allows a real number of toys, what must the discriminant equal?

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More Class 10 Discriminant and Nature of Roots practice

A shopkeeper in Jaipur sells x toys daily and his profit (in Rs) is modelled by −x2+20x−100. Setting the profit to a target T, he gets the equation x2−20x+(100+T)=0.For the highest target T that still allows a real number of toys, what must the discriminant equal?

Step-by-Step Solution

Master this chapter in 30 minutes a day.

More Class 10 Discriminant and Nature of Roots practice

A shopkeeper in Jaipur sells $x$ toys daily and his profit (in Rs) is modelled by $- x^{2} + 20 x - 100$ . Setting the profit to a target $T$ , he gets the equation $x^{2} - 20 x + (100 + T) = 0$ .
For the highest target $T$ that still allows a real number of toys, what must the discriminant equal?