Question

In ∆DEF, ∠D = 90° and EF – DE = 2 cm. If DF = 12 cm, find sec^2 E – cot^2F.

Answer 1

Answer:

n right angled ∆ABC

AB = 3 cm, BC = 12 cm

According to Pythagoras Theorem,

(AC)2 = (AB)2 + (BC)2

(AC)2 = (3)2 + (12)2

(ii) In right angled triangle ACD

AD = 13 cm, AC = √153

According to Pythagoras Theorem,

DC2 = AB2 - AC2

DC2 = 169 - 153

DC = √16 = 4 cm

∴ Length of DC is 4 cm

Explanation:

Answer 2

Answer:

4 cm is our main answer

Explanation:

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