Let a = 0 and p(x) be a polynomial of degree greater than 2. If p(x) l...
Let the remainder be R(x), then
R(x) = p(x)+q and R(a) = -a
Given R(-a) = a pa+q = -a -----(2)
-pa+q = a ----(1)
Solving (1) & (2), we get
p=-1, q=0
Therefore R(x) = -x
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Let a = 0 and p(x) be a polynomial of degree greater than 2. If p(x) l...
A+1 when divided by x and x+1, respectively, then p(x) has at least three distinct roots.
Proof:
Since p(x) leaves a remainder of 0 when divided by x-a, we know that p(a) = 0. Similarly, since p(x) leaves a remainder of a+1 when divided by x-(a+1), we know that p(a+1) = a+1.
Suppose for contradiction that p(x) has only two roots, say r and s, where r ≠ s. Then p(x) can be factored as p(x) = c(x-r)(x-s), where c is a constant. Since p(x) has degree greater than 2, we know that c ≠ 0.
Since p(a) = 0, we have c(a-r)(a-s) = 0. Since c ≠ 0, we must have either a = r or a = s. Without loss of generality, assume that a = r. Then p(x) can be written as p(x) = c(x-a)(x-s) = cx^2 - c(a+s)x + cas.
Now, since p(a+1) = a+1, we have c(a+1)^2 - c(a+s)(a+1) + cas = a+1. Simplifying, we get c(s-a) = 1, which implies that c ≠ 0 and s ≠ a.
Now, consider the polynomial q(x) = p(x) - (x-a)(x-(a+1)). Since p(x) and (x-a)(x-(a+1)) have the same remainders when divided by x and x+1, respectively, we have q(a) = q(a+1) = 0.
We can write q(x) as q(x) = cx^2 - c(a+s+1)x + cas + a(a+1). Note that q(x) has degree 2 and has roots a and a+1. Therefore, q(x) must be of the form q(x) = c(x-a)(x-(a+1)) = cx^2 - c(a+s+1)x + cas + a(a+1).
Comparing coefficients, we have c = 1 and cas + a(a+1) = 0. Since s ≠ a, we have c ≠ 0, which implies that s ≠ -(a+1). Therefore, we have cas + a(a+1) ≠ 0, which is a contradiction.
Therefore, our assumption that p(x) has only two roots is false. Thus, p(x) must have at least three distinct roots.
Let a = 0 and p(x) be a polynomial of degree greater than 2. If p(x) l...
Let P(x)=(x−a)(x+a)Q(x)+rx+s
When we divide by x+a, we get
P(−a)=(−a−a)(−a+a)Q(−a)+r(−a)+s=a
⇒s−ra=a ...(1)
And when we divide by x−a, we get
P(a)=(a−a)(a+a)Q(a)+ra+s=−a
⇒s+ra=−a ...(2)
Solving (1) and (2), we get
s=0,r=−1
Hence, P(x)=(x−a)(x+a)Q(x)−x
And when we divide by x2-a2, it leaves a remainder −x.
Hence option D is correct
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