Page 130 - Math SL HB Sem 1

I In the triangle PQR" PR=5 cm, QR=4 cm and PQ:6 cm.
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Calculale

hnt. 55.8D (0.473
(a) the size cf PQR ; radians)

O) the area of trianel" PQR hvts, l olt tiw,"

q The follorving diagram shos,s a trialgle ABC. s.here Ae'B rs 90', AB = , AC 2 arrd
3
=
\ BAC is 0,

)

2 C

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(u) show that tit o =
3

(b) Show that ,*Ze =#
9

h,'g , ".1
(c) Find the esact value of cos2B .
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