Question

what is the formula for vegetable oil

Answer 1

A vegetable oil is the oil extracted from a plant and is in liquid form at room temperature. If it is in solid form we call it fat. The vegetable oils contain triglycerides, Vegetable oils are generally extracted from the seeds. The oils contain saturated and unsaturated fatty acids.

Palm oil is (IUPAC name) Hexadecanoic acid with a formula:
$CH_3 (CH_2)_{14} COOH$

Coconut oil is Octanoic acid:
$CH_3(CH_2)_6 COOH$

Peanut oil is Icosanoic acid:
$CH_3 (CH_2)_{18} COOH$

Butter is Butanoic acid with formula: We do not use it as oil in general.
$CH_3 (CH_2)_2 COOH$

Vinegar is Ethanoic acid with formula:
$CH_3 COOH$ . We do not use this as cooking oil in general.

there are other vegetable oils too.