Question

please check the NOTE!! in the attachment before answering!!

✧Question :
$\\ Q. \: If \: A= \frac{\pi}{5} , \: then \: find \: the \: value \: of\: : \\ \\ \sum _{r = 1}^{8} \: tan(rA).tan(r + 1)A$
​

Answer 1

Step-by-step explanation:

Given, Principal (P) = Rs. 62,500

Rate =8 % per annum or 4 % per half year

Number of years = 1

2

1

There will be 3 half years in 1

2

1

years.

We know,

A=P[1+

100

R

]

n

⇒A=62500[1+(

100

4

)

3

]

⇒A=62500×

25

26

×

25

26

×

25

26

⇒A=70304

compound interest =A−P

= Rs. 70304 - Rs. 62500

= Rs.7,804.

Answer 2

Answer:

question is from class 11th, trigonometry section!

✧Question :

\begin{gathered}\\ Q. \: If \: A= \frac{\pi}{5} , \: then \: find \: the \: value \: of\: : \\ \\ \sum _{r = 1}^{8} \: tan(rA).tan(r + 1)A\end{gathered}

Q.IfA=

5

π

,thenfindthevalueof:

r=1

∑

8

tan(rA).tan(r+1)A