Question

a) Show that the cosine rule shown below can be rearranged to give $\cos A = \frac{b^2 + c^2 - a^2}{2bc}$ b) What is the size of angle $\theta$ in the triangle below? Give your answer to the nearest degree. Cosine rule $a^2 = b^2 + c^2 - 2bc \cos A$ 17 mm 26 mm $\theta$ 14 mm Not drawn accurately

          a) Show that the cosine rule shown below can
be rearranged to give
$\cos A = \frac{b^2 + c^2 - a^2}{2bc}$
b) What is the size of angle $\theta$ in the triangle
below?
Give your answer to the nearest degree.
Cosine rule
$a^2 = b^2 + c^2 - 2bc \cos A$
17 mm
26 mm
$\theta$
14 mm
Not drawn accurately

a) Show that the cosine rule shown below can
be rearranged to give
cos A = (b^2 + c^2 - a^2)/(2bc)
b) What is the size of angle θ in the triangle
below?
Give your answer to the nearest degree.
Cosine rule
a^2 = b^2 + c^2 - 2bc cos A
17 mm
26 mm
θ
14 mm
Not drawn accurately

Added by Martin F.

Elementary and Intermediate Algebra

Alan S. Tussy, R. David Gustafson 5th Edition

Instant Answer

Solved by Expert Benjamin Densmore

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a) Show that the cosine rule shown below can be rearranged to give b^2 + c^2 - 2ab cos A = 2bc b) What is the size of angle Î¸ in the triangle below? Give your answer to the nearest degree. Cosine rule a^2 = b^2 + c^2 - 2bc cos A 17 mm B 26 mm A 14mm 6 Not drawn accurately