"check whether" is a correct and usable phrase in written English. You can use it when you want to ask someone to verify whether something is true or not. For example: Please check whether the address on this form is correct.
Check whether VAT is included.
Check whether your company offers a disease management program.
He sniffs the ovens to check whether anything is burning.
Can I check whether my answers are correct?
"Do your research and check whether your industry is advertising.
Check whether Φ k = ϕ.
For each, check whether (21).
I love the desktop app, it’s always running on my Mac. Ludwig is the best English buddy, it answers my 100 queries per day and stays cool.
Cristina Valenza
Retail Lead Linguist @ Apple Inc.