Q4 of 164 Page 44

Show that

cos 48° – sin 42° = 0


Simplifying the left hand side:

⇒ cos 48° – cos(90–42)


⇒ cos 48° – cos(48)°


⇒ 0


Which is equal to right hand side.


Hence proved.


More from this chapter

All 164 →
3

Find A if

(i) sin A = cos 30°


(ii) tan49° = cot A


(iii) tan A tan 35° = 1


(iv) sec 35° = cosec A


(v) cosec A cos 43° = 1


(vi) sin 20° tan A sec 70° = √3

 3

Find A if

(i) sin A = cos 30°


(ii) tan49° = cot A


(iii) tan A tan 35° = 1


(iv) sec 35° = cosec A


(v) cosec A cos 43° = 1


(vi) sin 20° tan A sec 70° = √3

 4

Show that

cos 48° – sin 42° = 0

 4

Show that

cos 20° cos 70° – sin 70° sin 20° = 0