Consider the arithmetic sequence .
Find an expression for the term.
Write down the sum of the first n terms using sigma notation.
Calculate the sum of the first 15 terms.
EduNinjaConsider the arithmetic sequence 8,26,44,….
Find an expression for the nth term.
Write down the sum of the first n terms using sigma notation.
Calculate the sum of the first 15 terms.
The sum of the first 16 terms of an arithmetic sequence is 212 and the fifth term is 8 .
Find the first term and the common difference.
Find the smallest value of n such that the sum of the first n terms is greater than 600 .
Find the sum of all the multiples of 3 between 100 and 500 .
Find the value of k if ∑r=1∞k(31)r=7.
Let f(n)=n5−n,n∈Z+.
Find the values of f(3), f(4) and f(5).
1.
Find the sum of all integers, between 10 and 200, which are divisible by 7 .
Express the above sum using sigma notation.
An arithmetic sequence has first term 1000 and common difference of -6 . The sum of the first n terms of this sequence is negative.
Find the least value of n.
Given the sets A and B, use the properties of sets to prove that A∪(B′∪A)′=A∪B, justifying each step of the proof.
In this question the notation (anan−1…a2a1a0)b is used to represent a number in base b, that has unit digit of a0. For example (2234) 5 represents 2×53+2×52+3×5+4=319 and it has a unit digit of 4 .
Let x be the cube root of the base 7 number (503231)7.
By converting the base 7 number to base 10 , find the value of x, in base 10 .
Express x as a base 5 number.
Let y be the base 9 number (anan−1…a1a0)9. Show that y is exactly divisible by 8 if and only if the sum of its digits, ∑i=0nai, is also exactly divisible by 8 .
Using the method from part (b), find the unit digit when the base 9 number (321321321)9 is written as a base 8 number.
The fifth term of an arithmetic sequence is equal to 6 and the sum of the first 12 terms is 45 . Find the first term and the common difference.
Use the Euclidean algorithm to show that 1463 and 389 are relatively prime.
Find positive integers a and b such that 1463 a-389 b=1.