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For the equation x2 + (2k+2)x + 2k+5 = 0, find the value(s) of k for which the roots are equal. If k>0, find the roots of the new equation whose roots are 2 extalpha + extalpha extbeta and 2 extbeta +

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2. (i) (a)

  1. Identify the coefficients of the quadratic equation x2+(2k+2)x+2k+5=0x^2 + (2k+2)x + 2k+5 = 0.

    The coefficients are a=1a=1, b=(2k+2)b=(2k+2), and c=(2k+5)c=(2k+5).

  2. Apply the condition for equal roots.

    For the roots α\alpha and β\beta to be equal (α=β\alpha = \beta), the discriminant (Δ\Delta) of the quadratic equation must be zero.

    Δ=b2−4ac=0\Delta = b^2 - 4ac = 0 (2k+2)2−4(1)(2k+5)=0(2k+2)^2 - 4(1)(2k+5) = 0
  3. Solve the equation for kk.

    4(k+1)2−4(2k+5)=04(k+1)^2 - 4(2k+5) = 0

    Divide the entire equation by 4:

    (k+1)2−(2k+5)=0(k+1)^2 - (2k+5) = 0

    Expand the square:

    k2+2k+1−2k−5=0k^2 + 2k + 1 - 2k - 5 = 0 k2−4=0k^2 - 4 = 0 k2=4k^2 = 4 k=±4k = \pm \sqrt{4} k=2 or −2k = \boxed{2 \text{ or } -2}

    2. (i) (b)

  4. Use the condition k>0k > 0 to select the value of kk.

    From part (a), the positive value for kk is k=2k=2.
    Substitute k=2k=2 into the original quadratic equation to find its roots:

    x2+(2(2)+2)x+2(2)+5=0x^2 + (2(2)+2)x + 2(2)+5 = 0 x2+(4+2)x+(4+5)=0x^2 + (4+2)x + (4+5) = 0 x2+6x+9=0x^2 + 6x + 9 = 0

    This equation can be factored as (x+3)2=0(x+3)^2 = 0.
    So, the roots are α=−3\alpha = -3 and β=−3\beta = -3.

  5. Calculate the new roots.

    The new roots are given as r1=2α+αβr_1 = 2\alpha + \alpha\beta and r2=2β+αβr_2 = 2\beta + \alpha\beta.
    Using α=−3\alpha = -3 and β=−3\beta = -3:
    First, calculate αβ=(−3)(−3)=9\alpha\beta = (-3)(-3) = 9.

    r1=2(−3)+9=−6+9=3r_1 = 2(-3) + 9 = -6 + 9 = 3 r2=2(−3)+9=−6+9=3r_2 = 2(-3) + 9 = -6 + 9 = 3

    The new roots are 3 and 3.

  6. Form the new quadratic equation.

    A quadratic equation with roots r1r_1 and r2r_2 is given by $x^2 - (r

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