It is known that,
\(\overline{x^3 + y^3 + z^3 - 3xyz} =\overline{ (x + y + z)(x^2 + y^2 + z^2 - xy - yz - zx)}\)
put x + y + z = 0,
x3 + y3 + z3 - 3xyz = (0) (x2 + y2 + z2 - xy - yz - zx)
= x3 + y3 + z3 - 3xyz = 0
= x3 + y3 + z3 = 3xyz
Write the coefficients of x 2 in each of the following:
(i) 2 + x 2 + x
(ii) 2 – x 2 + x 3
(iii) \(\frac{π }{ 2}\) x2 + x
(iv) √2 x -1
Which of the following expressions are polynomials in one variable and which are not? State reasons for your answer.
(i) 4x 2 – 3x + 7
(ii) y 2 + √2
(iii) 3 √t + t√2
(iv) y +\(\frac{ 2 }{ y} \)
(v) x 10 + y 3 + t 50
What are the possible expressions for the dimensions of the cuboids whose volumes are given below?
(i) Volume : 3x 2 – 12x
(ii) Volume : 12ky2 + 8ky – 20k
Give possible expressions for the length and breadth of each of the following rectangles, in which their areas are given:
(i) Area : 25a 2 – 35a + 12
(ii) Area : 35y 2 + 13y –12
In Fig. 9.26, A, B, C and D are four points on a circle. AC and BD intersect at a point E such that ∠ BEC = 130° and ∠ ECD = 20°. Find ∠ BAC.