Skip to main contentSkip to solution

If xx is a real number such that max(min(x,2x),x4,2x8)=π3\max(\min(x, 2 - x), x - 4, 2x - 8) = \pi - 3, then the number of possible values of xx is

Solution

Correct Option: 1

Let T=π30.14T = \pi - 3 \approx 0.14. The equation is max(min(x,2x), x4, 2x8)=T\max(\min(x, 2-x),\ x-4,\ 2x-8) = T.

For the maximum to equal TT, at least one of the three quantities must equal TT, and none can exceed TT.


Case 1: min(x,2x)=T\min(x, 2-x) = T.

If x1x \leq 1, min=x=T\min = x = T, so x=T0.14x = T \approx 0.14.

If x1x \geq 1, min=2x=T\min = 2-x = T, so x=2T1.86x = 2 - T \approx 1.86.

For each, check the other two are T\leq T:

At x=Tx = T: x43.86x - 4 \approx -3.86, 2x87.722x - 8 \approx -7.72. Both T\leq T. Valid.

At x=2Tx = 2 - T: x42.14x - 4 \approx -2.14, 2x84.282x - 8 \approx -4.28. Both T\leq T. Valid.


Case 2: 2x8=T2x - 8 = T, so x=T+824.07x = \dfrac{T + 8}{2} \approx 4.07.

Check others T\leq T:

min(x,2x)=2x2.07T\min(x, 2-x) = 2 - x \approx -2.07 \leq T. Valid.

x4=T+824=T20.07Tx - 4 = \dfrac{T + 8}{2} - 4 = \dfrac{T}{2} \approx 0.07 \leq T. Valid.

Valid solution.


Case 3: x4=Tx - 4 = T, so x=T+44.14x = T + 4 \approx 4.14.

Check 2x8=2T+88=2T0.282x - 8 = 2T + 8 - 8 = 2T \approx 0.28. But 2T>T2T > T, contradicting the maximum being TT. Invalid.


Total valid values of xx: two from Case 11 and one from Case 22.

Answer =3= 3

Keyboard Shortcuts

  • Left arrow: Previous question
  • Right arrow: Next question
  • S key: Jump to solution
  • Q key: Jump to question