cosine (noun)/ˈkəʊ.saɪn/ — In a right triangle, the ratio of the length of the side adjacent to an acute angle to the length of the hypotenuse. Symbol: cos
cosign, co-sign, co sign all sound exactly like cosine but have different meanings and spellings. Mixing these up is one of the most common spelling mistakes in English.
cosine
noun
In a right triangle, the ratio of the length of the side adjacent to an acute angle to the length of the hypotenuse. Symbol: cos
cosign
noun
The promotion of one musical artist (usually less successful) by another.
Full definition →co-sign
verb
To sign a document jointly with another person, sometimes as an endorsement.
Full definition →How to Remember the Difference
- → Focus on meaning first — once you know what each word means, the correct spelling follows naturally.
- → Write a test sentence for each word and save it as a reference.
- → When in doubt, look up the definition — if it doesn't match your sentence, switch to the homophone.
Frequently Asked Questions
What is a homophone of cosine?
cosign, co-sign, co sign are homophones of "cosine". They sound identical when spoken but have different meanings and spellings.
What is the difference between cosine and cosign?
"cosine" means: In a right triangle, the ratio of the length of the side adjacent to an acute angle to the length of the hypotenuse. Symbol: cos. "cosign" means: The promotion of one musical artist (usually less successful) by another.. They sound the same but are used in completely different contexts.
What is a homophone?
A homophone is a word that sounds exactly like another word but has a different meaning and often a different spelling. Examples include "their / there / they're", "to / too / two", and "cosine / cosign". Homophones are a common source of spelling and grammar mistakes.
How do I remember the difference between cosine and cosign?
A good strategy is to memorize a short sentence that uses each word correctly, then recall that sentence when you are unsure. For example, focus on the meaning first — then let the spelling follow from context. Reading and writing regularly also helps these distinctions become automatic.