Find the equation of the line that is perpendicular to 3x + 2y – 8 = 0 and passes througthe mid-point of the line segment joining the points (5,-2) and (2, 2).11bt lino passing through the intersection of 2 + 51 – 4II About the author Allison
Given :- If α and β are the zeros of the quadratic polynomial f(x) = kx² + 4x + 4 such that α² + β² = 24, To Find :- Value of k Solution :- Sum of zeroes \pmb { \alpha + \beta = \dfrac{ – b}{a}} α+β= a −b α+β= a −b \alpha + \beta = \dfrac{ – 4}{k}α+β= k −4 Product of zeroes \pmb{ \alpha \beta = \dfrac{c}{a}} αβ= a c αβ= a c \sf\alpha \beta = \dfrac{4}{k}αβ= k 4 Apply Identity { \bigg( \alpha + \beta \bigg)}^{2} = { \alpha }^{2} + 2 \alpha \beta + { \beta }^{2}(α+β) 2 =α 2 +2αβ+β 2 \sf { \bigg(\dfrac{ – 4}{k} } \bigg)^{2} = 24 + 2 \dfrac{4}{k}( k −4 ) 2 =24+2 k 4 \sf\dfrac{16}{ {k}^{2} } = 24 + 8k k 2 16 =24+8k \sf \: 16 = 24 {k}^{2} + 8k16=24k 2 +8k \sf \: \dfrac{16}{8} = 24k {}^{2} + k 8 16 =24k 2 +k \sf \: 2 = 24 {k}^{2} + k2=24k 2 +k \sf \: 3 {k}^{2} + k – 2 = 03k 2 +k−2=0 \sf \: 3 {k}^{2} + (3k – 2k) – 2 = 03k 2 +(3k−2k)−2=0 \sf \: (3k – 2) \: or \: (k + 1)(3k−2)or(k+1) k = 2/3 Or k = -1 Reply
Given :-
If α and β are the zeros of the quadratic polynomial f(x) = kx² + 4x + 4 such that α² + β² = 24,
To Find :-
Value of k
Solution :-
Sum of zeroes
\pmb { \alpha + \beta = \dfrac{ – b}{a}}
α+β=
a
−b
α+β=
a
−b
\alpha + \beta = \dfrac{ – 4}{k}α+β=
k
−4
Product of zeroes
\pmb{ \alpha \beta = \dfrac{c}{a}}
αβ=
a
c
αβ=
a
c
\sf\alpha \beta = \dfrac{4}{k}αβ=
k
4
Apply Identity
{ \bigg( \alpha + \beta \bigg)}^{2} = { \alpha }^{2} + 2 \alpha \beta + { \beta }^{2}(α+β)
2
=α
2
+2αβ+β
2
\sf { \bigg(\dfrac{ – 4}{k} } \bigg)^{2} = 24 + 2 \dfrac{4}{k}(
k
−4
)
2
=24+2
k
4
\sf\dfrac{16}{ {k}^{2} } = 24 + 8k
k
2
16
=24+8k
\sf \: 16 = 24 {k}^{2} + 8k16=24k
2
+8k
\sf \: \dfrac{16}{8} = 24k {}^{2} + k
8
16
=24k
2
+k
\sf \: 2 = 24 {k}^{2} + k2=24k
2
+k
\sf \: 3 {k}^{2} + k – 2 = 03k
2
+k−2=0
\sf \: 3 {k}^{2} + (3k – 2k) – 2 = 03k
2
+(3k−2k)−2=0
\sf \: (3k – 2) \: or \: (k + 1)(3k−2)or(k+1)
k = 2/3
Or
k = -1