1.

If one root of the equation ax2 + x – 3 = 0 is –1, then what is the other root ?(a) \(\frac14\)(b) \(\frac{1}{2}\)(c) \(\frac34\)(d) 1

Answer»

(c) \(\frac{3}{4}\)

Let the other root of the equation ax2 + x – 3 = 0 be α. 

As (–1) is a root of the given equation, it satisfies the given equation, i.e., a (–1)2 + (–1) –3 = 0 ⇒ a – 1 – 3 = 0 ⇒ a = 4. 

∴ The equation becomes 4x2 + x – 3 = 0. 

Now, product of roots = α x (–1) = – \(\frac{3}{4}\) 

∴ α = 3 .



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