In a quadratic equation, with leading coefficient 1. Sheela reads the coefficient 16 of x wrongly as
19 and obtains the roots as -15 and -4. Which of the following are the correct roots of the
equation?
(a) 8, 8 (b) 6, 10
(c) -6, -10 (d) 12, 5
Coefficient 1.reads the coefficient 16 of x wrongly as 19 and obtains the roots as -15 and -4?
- Posted:
- 3+ months ago by rameshkss3
- Topics:
- root, read, leading, equations
Details:
Answers (1)
A big part of math is pattern recognition. A lot of homework is just fighting with stuff so you will remember the pattern when you see it again. The most common pattern is (x + a) * (x + b) = x^2 + (a + b)x + ab and the special case (x + a) * (x - a) = x^2 - a^2. When you spot the pattern you can just write the answer from memory.
Now study this page until it seems obvious: en.wikipedia.org/wiki/Polynomial_remainder_theorem
The first thing we notice is that -15 and -4 do not add to give +19, so the problem is a mess from the start. Answers (c) and (d) do not add to give 16, so they both are out. There is insufficient information to choose (a) or (b).