Olympiad workbook
- Exam
- Olympiad workbook
- Subject
- IOQM
- Chapter
- Quadratic Equation
Olympiad workbook · IOQM · Quadratic Equation
Let t be the area of a regular pentagon with each side equal to 1 ....
Let be the area of a regular pentagon with each side equal to 1 . Let be the polynomial equation with least degree, having integer coefficients, satisfied by and the gcd of all the coefficients equal to 1 . If is the sum of the absolute values of the coefficients of . What is the integer closest to .
Correct answer
16
Step-by-step solution
\text { Area of regular pentagon }=\frac{a^2 n}{4 \tan \left(\frac{180}{n}\right)}
No. of sides
Length of side
For regular pentagon by side length 1 ,
Now, to be found with least degree and integer coefficient soon that gcd of all coefficient is 1 .
Let
is the polynomial which satisfied all the conditions.
But this question can have multiple solutions as student can take \tan 36 as or even 0.7. Every time we will get different answers. So this question should be Bonus.