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Polynomials Class 10

Introduction

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This video focuses on mastering polynomials by exploring their key concepts, solving important questions, and learning effective tips and tricks for problem-solving. Viewers are encouraged to actively participate by practicing along with the content using pen and paper. Additional resources for practice can be found on Manoj Academy's website.

Zeros

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Understanding Zeros and Roots of Polynomials Zeros or roots of a polynomial are the values of x that make the polynomial equal to zero. For example, in the quadratic equation x² - 5x + 6 = 0, factorizing gives (x-3)(x-2)=0, so zeros are x=2 and x=3. These terms can be used interchangeably as they represent solutions where the polynomial equals zero.

Relation Between Zeros and Coefficients in Quadratic Polynomials In a quadratic polynomial ax²+bx+c with coefficients a≠0, there is an important relationship between its zeros (α & β) and coefficients: α+β=-b/a (sum), αβ=c/a (product). Using these relations allows rewriting any such quadratic as X²-(α+β)X+(αβ). This connection simplifies understanding polynomials' structure through their roots.

Example

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Finding and Verifying Zeros of a Quadratic Polynomial To find the zeros of the polynomial \(\sqrt{3}x^2 - 8x + 4\sqrt{3}\), set it to zero and use middle-term factorization. The factors are \((\sqrt{3}x-2)(x-2\sqrt{3})=0\), yielding roots \( x = 2/\sqrt{3}, x = 2"). Verification involves using formulas: sum of zeros equals \(-B/A) (here, resulting in "8/√"), while product equals C/A (resulting in "4"). Both calculations confirm consistency with coefficients.

Determining Coefficients from Given Roots Given roots for a quadratic equation, substitute them into its general form to derive equations involving coefficients. For example, substituting given values like X=−1 or X=-6 yields two linear equations that can be solved simultaneously determine unknowns precisely .

Final Question

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The problem involves finding the value of 'a' in a quadratic polynomial ax² - 6x - 6, given that the product of its zeros is 4. The concept hinges on using relationships between coefficients and roots: for any quadratic equation ax² + bx + c = 0, the product of zeros equals c/a. Applying this formula here gives (-6)/a = 4; solving it yields a as -3.