Understand Relationship: Understand the relationship between sec(θ) and sin(θ). Secant is the reciprocal of cosine, and sine and cosine are related through the Pythagorean identity: sin2(θ)+cos2(θ)=1. To find sec(θ), we need to find cos(θ) first and then take its reciprocal.
Find Cosine: Use the given value of sin(θ) to find cos(θ). We are given sin(θ)=13313. We can use the Pythagorean identity to find cos(θ): cos2(θ)=1−sin2(θ)cos2(θ)=1−[13313]2
Find Cosine: Find cos(θ).Since cos2(θ)=134, we take the square root of both sides to find cos(θ). However, we must consider both the positive and negative square roots because cosine can be positive or negative depending on the quadrant of θ. Since we are not given information about the quadrant, we will assume θ is in the first quadrant where cosine is positive:cos(θ)=134cos(θ)=132
Rationalize Denominator: Rationalize the denominator.To rationalize the denominator, we multiply the numerator and denominator by 13:cos(θ)=132×1313cos(θ)=13213
Find Secant: Find sec(θ).Secant is the reciprocal of cosine, so:sec(θ)=cos(θ)1sec(θ)=(13213)1sec(θ)=21313
Rationalize Denominator: Rationalize the denominator of sec(θ). To rationalize the denominator, we multiply the numerator and denominator by 13: sec(θ)=21313×1313sec(θ)=2×131313sec(θ)=213
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