Senior Manager
Joined: 27 Feb 2014
Posts: 489
Location: India
Concentration: General Management, International Business
GMAT 1: 570 Q49 V20 
GPA: 3.97
WE:Engineering (Education)
For which values of t, the parabola, y = tx^2 + 16tx + 68t
[#permalink]
16 Jan 2021, 22:46
y = tx^2 + 16xt + 68t
y = t (x^2 + 16x + 68)
Discriminant (D) of the quadratic equation x^2 + 16x + 68 = 16^2 - 4*1*68 = -16 (negative) that means roots are imaginary. In other words the parabola is not touching the x-axis.
Hence when t is positive, the parabola is upward whereas when t is negative, the parabola is downward
IMO A _________________
Want to Prepare for Number Properties? Click on the link below:
https://www.amazon.in/dp/B08KBF6NB9/ref=cm_sw_r_wa_apa_SyZCFb0KJ6YZ0Want to Increase Quant Score? Reach out for 1 to 1 tutoring:
prestigiousclasses@gmail.com