﻿ If the graph of the function y = 16x2 + 8(a + 5) x – 7a – 5 is strictly above the x – axis, then ‘a’ must satisfy the inequality : Kaysons Education

# If The Graph Of The Function y = 16x2 + 8(a + 5) x – 7a – 5 Is Strictly above The X – Axis, Then ‘a’ Must Satisfy The Inequality

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## Question

### Solution

Correct option is

– 15 < a < –2

y has to be + ive

∴ since sign of 1st term is + ive, therefore the expression will be + ive   6 P. 1218 if Δ < 0 64 (a + 5)2 + 64 (7a + 5) < 0

a2 + 17 a + 30 < 0 or (a + 15) (a + 2) < 0

or – 15 < a < – 2

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