Doubt

25. How many real solutions does the equation x⁷ + 14x⁵ + 16x³ + 30x â€“ 560 = 0 have?
(1) 7 (2) 1
(3) 3 (4) 5

5 Answers

take the derivative of it which is

7x⁶+70x⁴+48x²+30>0
so it is an strictly increasing function

so it will the x axis once

hence one solution[1]

Correct but wat do u mean touch the x axis once?Why cant it have a soln for values not on x axis?

For a solution the curve has to intersect with x axis

kuch aisa banega(don't find the errors in the graph)

it is just an idea to explain

Thanks a lot manipal!!

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