Answer:

Step-by-step explanation:
A right angled ∆ is given to us and we need to find out the value of cos 45° ( with rationalized denominator ) . As we know that in a right angle ∆ , the value of cosine is ,
In the given triangle ,
- Value of base = 1
- Value of hypotenuse = √2
On substituting the respective values ,
For rationalizing the denominator , multiply numerator and denominator by √2 , we have,
Simplify ,
Answer:
The given series can be written as
4
∑ (5)^i
i = 0
We know that the series is
1+5+25+125+625
This is equal to
(5)^0 + (5)^1 + (5)^2 + (5)^3 + (5)^4
Thus,
For i from 0 to 4,
We get the general representation.