Other tags that relate to Complex Rotations
Engineering. Exponential and Logarithmic Functions. Rational and irrational numbers. Sine, cosine, tangent. Vectors. Rotations. Mathematical reasoning & proof. Matrices. Vector algebra. Complex numbers.There are 41 results
Broad Topics > Algebraic expressions, equations and formulae > Inequalities
Eyes Down
Age 16 to 18
Challenge Level
The symbol [ ] means 'the integer part of'. Can the numbers [2x]; 2[x]; [x + 1/2] + [x - 1/2] ever be equal? Can they ever take three different values?
Big, Bigger, Biggest
Age 16 to 18
Challenge Level
Which is the biggest and which the smallest of $2000^{2002}, 2001^{2001} \text{and } 2002^{2000}$?
Rationals Between...
Age 14 to 16
Challenge Level
What fractions can you find between the square roots of 65 and 67?
After Thought
Age 16 to 18
Challenge Level
Which is larger cos(sin x) or sin(cos x) ? Does this depend on x ?
Approximating Pi
Age 14 to 18
Challenge Level
By inscribing a circle in a square and then a square in a circle find an approximation to pi. By using a hexagon, can you improve on the approximation?
Climbing
Age 16 to 18
Challenge Level
Sketch the graphs of y = sin x and y = tan x and some straight lines. Prove some inequalities.
Tetra Inequalities
Age 16 to 18
Challenge Level
Prove that in every tetrahedron there is a vertex such that the three edges meeting there have lengths which could be the sides of a triangle.
All-variables Sudoku
Age 11 to 18
Challenge Level
The challenge is to find the values of the variables if you are to solve this Sudoku.
Random Inequalities
Age 16 to 18
Challenge Level
Can you build a distribution with the maximum theoretical spread?
Fracmax
Age 14 to 16
Challenge Level
Find the maximum value of 1/p + 1/q + 1/r where this sum is less than 1 and p, q, and r are positive integers.
Unit Interval
Age 16 to 18 Short
Challenge Level
Can you prove our inequality holds for all values of x and y between 0 and 1?
Tet-trouble
Age 14 to 16
Challenge Level
Is it possible to have a tetrahedron whose six edges have lengths 10, 20, 30, 40, 50 and 60 units?
Unit Interval
Age 14 to 18
Challenge Level
Take any two numbers between 0 and 1. Prove that the sum of the numbers is always less than one plus their product?
Classical Means
Age 16 to 18
Challenge Level
Use the diagram to investigate the classical Pythagorean means.
Proofs with Pictures
Age 14 to 18
Some diagrammatic 'proofs' of algebraic identities and inequalities.
Quadratic Harmony
Age 16 to 18
Challenge Level
Find all positive integers a and b for which the two equations: x^2-ax+b = 0 and x^2-bx+a = 0 both have positive integer solutions.
Farey Neighbours
Age 16 to 18
Challenge Level
Farey sequences are lists of fractions in ascending order of magnitude. Can you prove that in every Farey sequence there is a special relationship between Farey neighbours?
Erratic Quadratic
Age 16 to 18
Challenge Level
Can you find a quadratic equation which passes close to these points?
Discrete Trends
Age 16 to 18
Challenge Level
Find the maximum value of n to the power 1/n and prove that it is a maximum.
Without Calculus
Age 16 to 18
Challenge Level
Given that u>0 and v>0 find the smallest possible value of 1/u + 1/v given that u + v = 5 by different methods.
Comparing Continued Fractions
Age 16 to 18
Challenge Level
Which of these continued fractions is bigger and why?
Exhaustion
Age 16 to 18
Challenge Level
Find the positive integer solutions of the equation (1+1/a)(1+1/b)(1+1/c) = 2
Code to Zero
Age 16 to 18
Challenge Level
Find all 3 digit numbers such that by adding the first digit, the square of the second and the cube of the third you get the original number, for example 1 + 3^2 + 5^3 = 135.
Square Mean
Age 14 to 16
Challenge Level
Is the mean of the squares of two numbers greater than, or less than, the square of their means?
Power Up
Age 16 to 18
Challenge Level
Show without recourse to any calculating aid that 7^{1/2} + 7^{1/3} + 7^{1/4} < 7 and 4^{1/2} + 4^{1/3} + 4^{1/4} > 4 . Sketch the graph of f(x) = x^{1/2} + x^{1/3} + x^{1/4} -x
Reciprocals
Age 16 to 18
Challenge Level
Prove that the product of the sum of n positive numbers with the sum of their reciprocals is not less than n^2.
Diverging
Age 16 to 18
Challenge Level
Show that for natural numbers x and y if x/y > 1 then x/y>(x+1)/(y+1}>1. Hence prove that the product for i=1 to n of [(2i)/(2i-1)] tends to infinity as n tends to infinity.
Giants
Age 16 to 18
Challenge Level
Which is the bigger, 9^10 or 10^9 ? Which is the bigger, 99^100 or 100^99 ?
Mediant Madness
Age 14 to 16
Challenge Level
Kyle and his teacher disagree about his test score - who is right?
' Tis Whole
Age 14 to 18
Challenge Level
Take a few whole numbers away from a triangle number. If you know the mean of the remaining numbers can you find the triangle number and which numbers were removed?
Integral Inequality
Age 16 to 18
Challenge Level
An inequality involving integrals of squares of functions.
Squareness
Age 16 to 18
Challenge Level
The family of graphs of x^n + y^n =1 (for even n) includes the circle. Why do the graphs look more and more square as n increases?
Biggest Enclosure
Age 14 to 16
Challenge Level
Three fences of different lengths form three sides of an enclosure. What arrangement maximises the area?
Not Continued Fractions
Age 14 to 18
Challenge Level
Which rational numbers cannot be written in the form x + 1/(y + 1/z) where x, y and z are integers?
Shades of Fermat's Last Theorem
Age 16 to 18
Challenge Level
The familiar Pythagorean 3-4-5 triple gives one solution to (x-1)^n + x^n = (x+1)^n so what about other solutions for x an integer and n= 2, 3, 4 or 5?
Two Cubes
Age 14 to 16
Challenge Level
Two cubes, each with integral side lengths, have a combined volume equal to the total of the lengths of their edges. How big are the cubes? [If you find a result by 'trial and error' you'll need to. . . .
NRICH is part of the family of activities in the Millennium Mathematics Project.