Q 01/05

In the trig mnemonic SOH-CAH-TOA, the letter O appears twice; which word does it stand for both times?

A) Orthogonal

B) Obtuse

C) Opposite

D) Origin

Answer · why

C) Opposite

Opposite is the O in both SOH and TOA: sine is opposite over hypotenuse and tangent is opposite over adjacent. The mnemonic is often sounded out as on...

Q 02/05

Mount Everest is named after George Everest, who directed the trigonometric mapping of India in which post?

A) Surveyor General

B) Governor-General

C) Astronomer Royal

D) Chief Engineer

Answer · why

A) Surveyor General

Surveyor General of India was his title, yet George Everest never saw the peak. His successor Andrew Waugh proposed the name after years of triangle c...

Q 03/05

The tangent function takes its name from the Latin word tangens, which describes a line doing what to a circle?

A) Cutting

B) Enclosing

C) Bisecting

D) Touching

Answer · why

D) Touching

Touching is the meaning: a tangent line just grazes a circle at a single point. The secant, from the Latin secans for 'cutting', is the line that slic...

Q 04/05

The degrees used in trigonometry are usually traced to Babylonian astronomers, who counted in which number system?

A) Base 10

B) Base 12

C) Base 20

D) Base 60

Answer · why

D) Base 60

Base 60 counting, known as sexagesimal, is also why one degree splits into 60 arcminutes and each arcminute into 60 arcseconds.

Q 05/05

Which Greek letter, the eighth in its alphabet, is the usual symbol for an unknown angle in trigonometry?

A) Sigma

B) Theta

C) Omega

D) Delta

Answer · why

B) Theta

Theta, written θ, stands for the unknown angle in formulas such as sin θ. Although it is the eighth letter, in the Greek numeral system it carried the...