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A:12+3V52-3V5atbu5find the values ofa and b. |
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Answer» the answer therefore is 40 a is 3 root 5 b 8s -3root 5 photo is not clear and it is of icic.board it will be -3 not sure Hence, we gota= -49/41b= -21/41 We need to find the values ofaaandbb, such that the polynomialx3−10x2+ax+bx^3-10x^2+ax+bis exactly divisible byx−1x-1as well asx−2x-2 Assume that :f(x)=x3−10x2+ax+bfx=x3-10x2+ax+b Using remainder theorem, we know that if a polynomialf(x)f(x)is divided byx−cx-c, the remainder isf(c)f(c)x−1=0⇒x=1x-1=0⇒x=1 Applying the factor theorem, we know that: f(x)will be exactly divisible by(x−1)iff(1)=0fxwill be exactly divisible byx-1iff1=0. Hence, we have: f(1)=13−10×12+a×1+b=(1−10+a+b)=−9+a+bf1=13-10×12+a×1+b=1-10+a+b=-9+a+b∴f(1)=0⇒a+b=9...(1)f1=0⇒a+b=9...1 The same method must be applied for the second factor as well,x−2=0⇒x=2x-2=0⇒x=2 Similarly, applying the factor theorem gives us: f(x)will be exactly divisible by(x−2)iff(2)=0fxwill be exactly divisible byx-2iff2=0. Hence, we have: f(2)=23−10×22+a×2+b=(8−40+2a+b)=−32+2a+bf2=23-10×22+a×2+b=8-40+2a+b=-32+2a+b∴f(2)=0⇒2a+b=32...(2)f2=0⇒2a+b=32...2 Solving simultaneously, by subtracting (1)from (2),we have:a=23Solving simultaneously, by subtracting (1)from (2),we have:a=23 Substituting the value ofainto11or22, we get the value ofbwhich is−-14.∴a= 23 andb=−-14 hence,wegot-49/41a -21/41 a= -49/41b= -12/41it is the right answerhope it helps u a=-49/41 b= -21/41 this is the answer a is 3 root 5b 8s-3root 5 a is 3 root 5b 8s -3root 5 first of all 2 + 3√5------------ = a + b√52 - 3√5 then2 + 3√5 2 + 3√5------------ x ---------- = a + b√52 - 3√5 2 + 3√5 4+ 45 +12√5------------------- = a + b√5 4 - 45 49 12√5---- - ----- = a + b√5-41 41 now comparison the both sides a = -49/41b = -12/41 A is 3 root 5 B is 8 -3 root 5 this is very right answer a= -49/45. and b=-12/41 this is write answer value of a is 49and value of b is 12 a=(-49/41)B=(-21/41) |
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