Use the diagram to identify a segment parallel to cf

a. dg
b. ad
c. dc
d. ab

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?

If tan2a=cot(a+60), find the value of a, where 2a is an acute angle

Asinusoidal function whose frequency is 1/6pi