Respuesta :
Solution
[tex] \text{Given a,b,c and d are in GP}[/tex]
[tex] \therefore \frac{b}{a} = \frac{ c}{b} = \frac{d}{c} = r \\ \\ \implies b = ar ,c = br,d = cr \implies \: b = ar,c = (ar)r,d = (br)r \\ \\ \implies b = ar,c = a {r}^{2} ,d = {br}^{2} \implies b = ar,c = {ar}^{2} ,d = (ar)r {}^{2} = a {r}^{3} ...(i)[/tex]
[tex] \text{Now, Consider}[/tex]
[tex]( {a}^{2} + {b}^{2} + {c}^{2} )( {b}^{2} + {c}^{2} + {d}^{2} ) = ( {a}^{2} + {a}^{2} {r}^{2} + ( {a}^{2} {r}^{4} )( {a}^{2} {r}^{2} + {a}^{2} r {}^{2} + {a}^{2} {r}^{4} + {a}^{2} {r}^{6} )[/tex]
[tex] = {a}^{2} (1 + {r}^{2} + {r}^{4} ) {a}^{2} {r}^{2} (1 + {r}^{2} + {r}^{4} ) = a {}^{4} {r}^{2} (1 + {r}^{2} + {r}^{4} ) {}^{2} = [a {}^{2}r(1 + {r}^{2} + {r}^{4}) ] {}^{2} [/tex]
[tex] = ( {a}^{2} r + {a}^{2} {r}^{3} + {a}^{2} r {}^{5} ) {}^{2} = (a. \: ar + ar. \: a {r}^{2} + a {r}^{2} .a {r}^{3} ) {}^{2} [/tex]
[tex] = (ab + bc + cd) {}^{2} \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \text{[From Equation (i)]}[/tex]
Hope This Helps!!! :)
The given polynomial can be rewritten as factors of the common ratio of
the geometric progression.
Response:
If a, b, c, d are in GP, (a² + b² + c²) × (b² + c² + d²) = [tex]\underline{(a\cdot b + b \cdot c + c\cdot d)^2}[/tex]
Which method can be used to analyze the given polynomial relation?
The assumed parameters are;
a, b, c, and d for a geometric sequence
Therefore;
[tex]\mathbf{\dfrac{b}{a}} = \dfrac{c}{b} = \dfrac{d}{c} = r[/tex]
Which gives;
b = a·r
c = b·r
d = c·r
Therefore;
c = b·r = a·r²
d = c·r = a·r³
(a² + b² + c²) × (b² + c² + d²) = (a² + (a·r)² + (a·r²)²) × ((a·r)² + (a·r²)² + (a·r³)²)
(a² + a²·r² + a²·r⁴) × ((a²·r²) + (a²·r⁴) + a²·r⁶) = a⁴·r²·(r⁸ + 2·r⁶ + 3·r⁴ + 2·r² + 1)
Which gives;
a⁴·r²·(r⁸ + 2·r⁶ + 3·r⁴ + 2·r² + 1) = a²·r·(r⁴ + r² + 1) × a²·r·(r⁴ + r² + 1)
a²·r·(r⁴ + r² + 1) × a²·r·(r⁴ + r² + 1) = (a²·r·(r⁴ + r² + 1))²
a²·r·(r⁴ + r² + 1) = a²·r⁵ + a²·r³ + a²·r
a²·r = a·b
a²·r³ = b·c
a²·r⁵ = c·d
Therefore;
a²·r⁵ + a²·r³ + a²·r = a·b + b·c + c·d
(a² + b² + c²) × (b² + c² + d²) = (a²·r·(r⁴ + r² + 1))² = [tex]\underline{(a\cdot b + b \cdot c + c\cdot d)^2}[/tex]
Learn more about geometric progression (GP.) here:
https://brainly.com/question/140530
