16) If A, B and C are interior angles of triangle ABC, then the value of is A, B మరియు C లు త్రిభుజం ABC లోని అంతర కోణాలైన, యొక్క విలువ
A)
B)
C)
D)
View Answer
C)
Explanation:🎯 Shortcut Method for the Given Expression:
We are given that , , and are the interior angles of a triangle, i.e., .
We need to find the value of:
Step 1: Use the fact that
Since the sum of the angles in a triangle is , we can substitute . Thus,
Step 2: Use the cosine of a difference
Now we have:
Using the co-function identity:
We get:
Final Answer:
This is the quickest method using the fact that the sum of the angles in a triangle is and applying trigonometric identities.
17) The value of cos 54° cos 36° – sin 54° sin 36° is cos 54° cos 36° – sin 54° sin 36° యొక్క విలువ
A) 0
B) 1
C)
D)
View Answer
A) 0
Explanation:🎯 Shortcut Method for Solving
The expression is a well-known cosine identity:
Step 1: Apply the cosine addition formula
Using the identity , we can rewrite the given expression as:
Step 2: Simplify
We know that:
Final Answer:
18) Which of the following rational number have terminating decimal? కింది వాటిలో ఏ అకరణీయ సంఖ్య అంతమయ్యే దశాంశాన్ని కలిగి ఉంటుంది?
A)
B)
C)
D)
View Answer
A)
Explanation:🎯 Shortcut Method to Determine if a Rational Number Has a Terminating Decimal
A rational number has a terminating decimal if and only if, when simplified, its denominator has no prime factors other than 2 and 5. In other words, the denominator of the fraction must be of the form , where and are non-negative integers.
Let’s check each option:
– 1.
– The denominator is 250, which factors as: – Since the denominator contains only the primes 2 and 5, this fraction will have a terminating decimal.
– 2.
– The denominator is 225, which factors as: – Since 225 has a factor of 3, it does not meet the condition for a terminating decimal.
– 3.
– The denominator is 18, which factors as: – Since 18 has a factor of 3, it does not meet the condition for a terminating decimal.
– 4.
– The denominator is 21, which factors as: – Since 21 has a factor of 3, it does not meet the condition for a terminating decimal.
Final Answer:
19) H.C.F. of 2023, 2024, 2025 is –
2023, 2024, 2025 ల యొక్క గ.సా.భా.
A) 2024
B) 2023
C) 0
D) 1
View Answer
D) 1
Explanation:🎯 Shortcut Method to Find the HCF of 2023, 2024, and 2025
The HCF (Highest Common Factor) of three numbers is the largest number that divides all of them exactly.
Step 1: Check the divisibility of 2023, 2024, and 2025
– The numbers 2023, 2024, and 2025 are consecutive numbers, which means:
– 2024 is one more than 2023, and one less than 2025.
– Consecutive numbers always have an HCF of 1, because there is no number greater than 1 that can divide all three.
Step 2: Conclude the HCF
Since these are consecutive numbers, their HCF is 1.
Final Answer:
20) A boy observed the top of an electric pole at an angle of elevation of 60° when the observation point is 6 meters away from the.foot of the pole, then the height of the pole is ఒక బాలుడు ఒక విద్యుత్ స్థంభం అడుగు భాగం నుండి 6 మీ. దూరంలో ఉన్న బిందువు నుండి విద్యుత్ స్థంభం పై భాగాన్ని 60° ఊర్ధ్వ కోణంతో పరిశీలించిన, ఆ స్థంభం ఎత్తు
A) 6 m
B)
C)
D)
View Answer
C)
Explanation:🎯 Shortcut Method Using Trigonometry (Tangent)
We are given the following information:
– The angle of elevation to the top of the electric pole is .
– The distance from the observation point to the foot of the pole is 6 meters.
To find the height of the pole, we can use the tangent of the angle of elevation. The tangent function is given by:
In this case:
–
– The distance from the pole = 6 meters
– We need to find the height of the pole.
So,
Since , we have:
Step 2: Solve for the height of the pole
Multiplying both sides by 6:
Thus, the height of the pole is:
Final Answer: