Yes, that is correct! The expression you provided is the Taylor series expansion of the square root of (1 + x) around x = 0. It is an infinite series that converges to the square root of (1 + x) for all values of x between -1 and 1.
The first few terms of the series are:
sqrt(1 + x) = 1 + (1/2)x - (1/8)x^2 + (1/16)x^3 - (5/128)x^4 + ...
Each term in the series is calculated using the formula:
((-1)^n * (2n)! / ((1-2n) * (n!)^2 * (4^n))) * x^n
where n is the index of the term and x is the value at which the series is evaluated.
The series can be used to approximate the value of the square root of (1 + x) to a desired degree of accuracy, by including a sufficient number of terms in the expansion. HP Instant Ink
We can use similar triangles to solve this problem.
Since DE is parallel to BC, we have ∠ECD = ∠ABC and ∠FDC = ∠ACB (alternate interior angles). Therefore, triangles ACD and DEF are similar.
Let x be the length of BD. Then, since AF = 9 and DF = 3, we have AB = AF + FB = 9 + x and BD = DF + FB = 3 + x.
Since triangles ACD and DEF are similar, we have
AC/CD = AD/DE
Substituting AC = AB - BC and CD = BD - BC, we get
(AB - BC)/(BD - BC) = AD/DE
Substituting AB = 9 + x and DE = BC, we get
(9 + x - BC)/(BD - BC) = AD/BC
Cross-multiplying, we get
AD = (9 + x - BC) × BC/(BD - BC)
Since triangles ABD and DFC are similar, we have
AD/DF = BD/FC
Substituting AD from the previous equation and DF = 3, we get
(9 + x - BC) × BC/(BD - BC) = BD/(BD - 3)
Cross-multiplying, we get
BD^2 - 6BD + 9 = BC × (9 + x)
Substituting BC = DE and using the fact that DE is parallel to BC, we have
BD^2 - 6BD + 9 = DE × (9 + x)
Substituting DE = BC and using the fact that EF is parallel to CD, we have
BD^2 - 6BD + 9 = EF × (BD - 3)
Substituting EF = CD - CF = BD - 3 and simplifying, we get
BD^2 - 12BD + 36 = 0
Factoring, we get
(BD - 6)^2 = 0
Therefore, BD = 6.
Thanks,
MyMorri Portal