Answer:
-1
Step-by-step explanation:
We need to find the value of tan² 70° -sec² 70°.
We know that,
...(1)
We can write the given expression as :
tan² 70° -sec² 70° = -(-tan² 70° +sec² 70°)
=-(sec² 70°-tan² 70°)
Using identity (1)
=-(1)
= -1
Hence, the value of the given expression is -1.
The values of X and Y are 30 and 11 respectively
<h3>How to determine the values of X and Y?</h3>The figure that represents the complete question is added as an attachment
The given parameters are:
DH = X +3
HF = 3Y
GH = 2X -5
HE = 5Y
From the attached parallelogram, we have:
DH = HF
GH = HE
Substitute the known values in the above equation
X + 3 = 3Y
2X - 5 = 5Y
Make X the subject in X + 3 = 3Y
X = 3Y - 3
Substitute X = 3Y - 3 in 2X - 5 = 5Y
2(3Y - 3) - 5 = 5Y
Expand
6Y - 6 - 5 = 5Y
Evaluate the like terms
Y = 11
Substitute Y = 11 in X = 3Y - 3
X = 3*11 - 3
Evaluate
X = 30
Hence, the values of X and Y are 30 and 11 respectively
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