solve the answer in properly way and please don't send other things
Answers
Step-by-step explanation:
Solutions:-
2)
Given that 1/(7+5√2)
We know that
The Rationalising factor of a+√b is a-√b
The denominator = 7+5√2
The Rationalising factor of 7+5√2 is 7-5√2
On Rationalising the denominator then
=> [1/(7+5√2)]×[ (7-5√2)/(7-5√2)]
=> [1×(7-5√2)]/(7+5√2)(7-5√2)]
=> (7-5√2)/[(7+5√2)(7-5√2)]
=> (7-5√2)/[7²-(5√2)²]
Since , (a+b)(a-b) = a²-b²
Where , a = 7 and b = 5√2
=> (7-5√2)/(49-50)
=> (7-5√2)/(-1)
=> -7+5√2
=> 5√2-7
3)
Given that (x-2)³
This is in the form of (a-b)³
Where, a = x and b = 2
We know that
(a-b)³ = a³-3a²b+3ab²-b³
=> (x-2)³ = x³-3(x²)(2)+3(x)(2)²-2³
=> (x-2)³ = x³-6x²+12x-8
The coefficient of x² is -6
Step-by-step explanation:
3 ans = The coefficient of (x - 2)³ =
- =-6
Given:
Expansion of (x - 2)³
To find:
The coefficient of (x - 2)³
Solution:
By formula, (a - 3ab²
78
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*
43
4.0
b)³ = a³-b³3a²b +
Substitute the values of a and b in the above formula, where a = x, b = 2
(x - 2)³ = x³ - 2³ - 3x² (2) + 3x (2)² (x - 2)³ = x³ 8 6x² + 12x
To find the coefficient of x² ,find the term with in the above equation,
Therefore, The coefficient of x² =-6
