# Reciprocal

What is the reciprocal of the sum of the reciprocals of 4 and 9?

**Result****Leave us a comment of example and its solution (i.e. if it is still somewhat unclear...):**

**Showing 0 comments:**

**Be the first to comment!**

#### To solve this example are needed these knowledge from mathematics:

## Next similar examples:

- Sum of members

What is the sum of the first two members of the aritmetic progression if d = -4.3 and a3 = 7.5? - Theorem prove

We want to prove the sentense: If the natural number n is divisible by six, then n is divisible by three. From what assumption we started? - Electronics: Resistors in parallel

From relation for calculating the resistance of parallel combination of resistors: ? Calculate the R, if R_{1}= 2Ω a R_{2}= 15Ω - Factory and divisions

The factory consists of three auxiliary divisions total 2,406 employees. The second division has 76 employees less than 1st division and 3rd division has 212 employees more than the 2nd. How many employees has each division? - Apples in baskets

Determine how many apples are in baskets when in the first basket are 4 apples, and in any other is 29 apples more than the previous, and we have eight baskets. - One half

One half of ? is: ? - Powers

Express the expression ? as the n-th power of the base 10. - 6 terms

Find the first six terms of the sequence. a1 = 7, an = an-1 + 6 - Series

Your task is express the sum of the following arithmetic series for n = 14: S(n) = 11 + 13 + 15 + 17 + ... + 2n+9 + 2n+11 - Nineteenth member

Find the nineteenth member of the arithmetic sequence: a1=33 d=5 find a19 - Vectors

For vector w is true: w = 2u-5v. Determine coordinates of vector w if u=(3, -1), v=(12, -10) - Trees

A certain species of tree grows an average of 0.5 cm per week. Write an equation for the sequence that represents the weekly height of this tree in centimeters if the measurements begin when the tree is 200 centimeters tall. - Two equations

Solve equations (use adding and subtracting of linear equations): -4x+11y=5 6x-11y=-5 - Functions f,g

Find g(1) if g(x) = 3x - x^{2}Find f(5) if f(x) = x + 1/2 - Volleyball

8 girls wants to play volleyball against boys. On the field at one time can be six players per team. How many initial teams of this girls may trainer to choose? - Linear system

Solve a set of two equations of two unknowns: 1.5x+1.2y=0.6 0.8x-0.2y=2 - Trigonometry

Is true equality? ?