<prompt> Hebufx frac2x 3kx - 2.Tafuta nambari zote halisi k ili f-1x fx.  <response>: Kutoka kwa hali f-1x fx, ff-1x ffx, ambayo hurahisisha hadi ff x x.Kumbuka hiloanzaalignffx f kushoto frac2x 3kx - 2 kulia frac2 cdot frac2x 3kx - 2 3k cdot frac2x 3kx - 2 - 2 frac22x 3 3kx - 2k2x 3 - 2kx - 2 frac4x 6 3kx - 62kx 3k - 2kx 4 frac3k 4x3k 4 x.endalignKwa hivyo, ffx x kwa nambari zote halisi k, isipokuwa wakati 3k 4 0, au k -43. Kumbuka kwamba wakati k -43,fx frac2x 3kx - 2 frac2x 3-frac43 x - 2 frac32x 3 -4x - 6 frac3 2x 3-2 2x 3 -frac32,hivyo fx haifanyi hivyo kuwa na kinyume. Kwa hivyo, jibu ni k in -infty,-frac43 cup -frac43,infty. 