If the sides of a are in AP and is the smallest side

MATHEMATICS · Single correct · A Level · Mathematics · Trigonometry · Trigonometry

Problem

If the sides of a

\triangle ABC

are in AP and

a

is the smallest side, then

\cos A

equals (1)

\dfrac{3c-4b}{2c}

(2)

\dfrac{3c-4b}{2b}

(3)

\dfrac{4c-3b}{2c}

(4) None of these