WAEC Mathematics 2012 Objective — Question 45

Question 45 of 50 from the West African Examinations Council (WAEC) Mathematics 2012 Objective paper, with the correct answer and a full explanation.

The graph is that of y=2x²−5x−3. Use it to answer questions 45 and 46. For what values of x will y be negative?

• A. -½≤x<3
• B. -½<x≤3
• C. -½<x<3Correct
• D. -½≤x≤3

Explanation

y<0 between the roots of 2x²−5x−3=0, which are x=−½ and x=3 (exclusive, since y=0 exactly at the roots), i.e. −½<x<3.

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