Emirp

1​3, 17, 79 are all examples of emirps.

C​an you work out what an emirp number is?

(​scroll for explanation)

A​n emirp (the word prime spelt backwards) is a prime number that remains prime even with its digits reversed (eg. 13 and 31 are both primes).

Prime Numbers

If you write the numbers from 82 down to 1 in descending order, you get a prime number (155 digits).

82818079787776757473727170...

Exponent

Exponent means the same as index or power.

I​t is used in the 'multiplication by itself' operation where the exponent (or index or power) indicates how many times a number should appear in the multiplication.

F​or example, in 5³ the ³ is the exponent telling us that number 5 should appear '3' times in the multiplication hence giving 5 × 5 × 5

Trigonometry

Trigonometry

Near-Death Experience?

What happens when you get 'scared half to death' twice?

Corresponding Angles

Corresponding angles are found when a transversal intersects a pair of parallel lines. These angles are on the same relative position when looking at the point of intersection.

C​orresponding angles are equal.

T​he pics below show the four pairs of corresponding angles which can be found.

Beauty in Maths

1 × 9 + 2 = 11
12 × 9 + 3 = 111
123 × 9 + 4 = 1111
1234 × 9 + 5 = 11111
12345 × 9 + 6 = 111111
123456 × 9 + 7 = 1111111
1234567 × 9 + 8 = 11111111
12345678 × 9 + 9 = 111111111

APR

APR stands for Annual Percentage Rate and gives the cost of borrowing money as a percentage of the amount borrowed.