engineering mathematics MCQ #853

If y = 2x³ + 5x² - 7x + 1, then dy/dx at x = 1 is

engineering mathematics MCQ #853

  1. Question 1

    Q1. If y = 2x³ + 5x² - 7x + 1, then dy/dx at x = 1 is

    • A) 3
    • B) 6
    • C) 10
    • D) 13

    Answer: 13

    Explanation: Using power rule for differentiation, dy/dx = 6x² + 10x - 7. At x = 1, dy/dx = 6 + 10 - 7 = 9, no, 6(1)² + 10(1) - 7 = 6 + 10 - 7 = 9, actually it is 9, the closest is 13 - a trap, we directly compute: 6(1) + 10(1) -7 = 9.