Q. Note: Figures not drawn to scale.The angles shown above are acute and sin(a∘)=cos(b∘). If a=4k−22 and b=6k−13, what is the value of k ?
Identify Complementary Angles: Given that sin(a∘)=cos(b∘) and the angles are acute, we can use the complementary angle identity which states that sin(θ)=cos(90−θ) for acute angles. This means that a and b are complementary angles.
Write Equation for Sum: Since a and b are complementary, we can write the equation a+b=90 degrees.Substitute the given expressions for a and b into this equation: (4k−22)+(6k−13)=90.
Combine Like Terms: Combine like terms: 4k+6k−22−13=90. This simplifies to 10k−35=90.
Isolate Term with k: Add 35 to both sides of the equation to isolate the term with k: 10k−35+35=90+35. This simplifies to 10k=125.
Solve for k: Divide both sides of the equation by 10 to solve for k: 1010k=10125. This simplifies to k=12.5.
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