Home
Class 14
MATHS
Consider the following sttements: 1. ...

Consider the following sttements:
1. `cos theta + sec theta` can never be equal to 1.5
2. `tan theta + cot theta` can never be less than 2

A

1 only

B

2 only

C

Both 1 and 2

D

Neither 1 nor 2

Text Solution

AI Generated Solution

The correct Answer is:
To solve the given statements, we will analyze each one step by step. ### Step 1: Analyze the first statement: `cos θ + sec θ = 1.5` 1. We can rewrite the expression using the definition of secant: \[ \sec \theta = \frac{1}{\cos \theta} \] Therefore, the expression becomes: \[ \cos \theta + \frac{1}{\cos \theta} \] 2. Let \( x = \cos \theta \). The expression now is: \[ x + \frac{1}{x} \] 3. We know from the AM-GM inequality that: \[ x + \frac{1}{x} \geq 2 \] for \( x > 0 \). The minimum value occurs when \( x = 1 \) (i.e., \( \theta = 0 \)). 4. Since \( x + \frac{1}{x} \) is always greater than or equal to 2, it can never be equal to 1.5. ### Conclusion for the first statement: The first statement is **true**. --- ### Step 2: Analyze the second statement: `tan θ + cot θ < 2` 1. We can rewrite the expression using the definition of cotangent: \[ \cot \theta = \frac{1}{\tan \theta} \] Therefore, the expression becomes: \[ \tan \theta + \frac{1}{\tan \theta} \] 2. Let \( y = \tan \theta \). The expression now is: \[ y + \frac{1}{y} \] 3. Again, using the AM-GM inequality: \[ y + \frac{1}{y} \geq 2 \] for \( y > 0 \). The minimum value occurs when \( y = 1 \) (i.e., \( \theta = 45^\circ \)). 4. Since \( y + \frac{1}{y} \) is always greater than or equal to 2, it can never be less than 2. ### Conclusion for the second statement: The second statement is **true**. --- ### Final Conclusion: Both statements are true. ---
Promotional Banner

Topper's Solved these Questions

  • TRIGONOMETRY

    PUNEET DOGRA|Exercise PREV YEAR QUESTIONS|163 Videos
  • STATISTICS

    PUNEET DOGRA|Exercise PRE YEAR QUESTIONS |163 Videos
  • VECTOR

    PUNEET DOGRA|Exercise Prev Year Questions|134 Videos

Similar Questions

Explore conceptually related problems

Consider the following statements : 1. "cos"theta+"sec"theta can never be equal to 1.5. 2. "sec"^(2)theta+"cosec"^(2)theta can never be less than 4. Which of the statements given above is/are correct ?

Prove that sec^(2)theta+cos^(2)theta can never be less than 2.

Prove that : (i) sec theta+cos theta can never be equal to (3)/(2) (ii) cosec^(2)theta+"sin"^(2) theta can never be less than 2.

Prove the following identity: (1+cot theta-cos ec theta)(1+tan theta+sec theta)=2

(cot theta)/((1-sin theta)(sec theta + tan theta)) is equal to :

(cot theta)/((1-sin theta) (sec theta + tan theta)) is equal to:

(i) Is the equation 2 cos^(2)theta + cos theta -6 =0 possible ? (ii) Is the equation 2 "sin"^(2)theta-costheta +4=0 can never be less than 2.

If cosec theta = 1.25 , then (sec theta + 4 cot theta -1)//(4 tan theta - 5 cos theta + 1 )=?

(cosec theta + sin theta) (sec theta - cos theta) tan theta + cot theta) is equal to

Prove that (sin theta- "cosec" theta )(cos theta- sec theta )=(1)/(tan theta + cot theta).

PUNEET DOGRA-TRIGONOMETRY-PREV YEAR QUESTIONS
  1. If cosec theta=(29)/(21),where 0 lt theta lt 90^@, then what is the va...

    Text Solution

    |

  2. Consider the following sttements: 1. cos theta + sec theta can neve...

    Text Solution

    |

  3. What is the length of the chord of a unit circle which subtends an ang...

    Text Solution

    |

  4. If tanA-tanB=x and cotB-cotA=y, then cot(A-B)=?

    Text Solution

    |

  5. What is sin(alpha+beta) - 2 sin alpha cos beta + sin(alpha- beta) =

    Text Solution

    |

  6. If 2tanA = 3tanB = 1, then what is tan(A-B) equal to?

    Text Solution

    |

  7. What is cos80^@ + cos 40^@ - cos20^@ equal to ?

    Text Solution

    |

  8. What is cot(A//2)-tan (A//2) equal to?

    Text Solution

    |

  9. What is cottheta+ cosecthetaequal to?

    Text Solution

    |

  10. What is tan25^@tan15^@ + tan15^@ tan 50^@ + tan25^@ tan50^@ equal to ?

    Text Solution

    |

  11. If sin theta=-1/2 and tan theta=(1)/(sqrt3) then in which quadrant doe...

    Text Solution

    |

  12. If cos theta + sin theta = sqrt2cos theta," then " cos theta -sin thet...

    Text Solution

    |

  13. In a circle of diameter 44 cm, the length of chord is 22cm. What is th...

    Text Solution

    |

  14. What is (1+tan alpha tan beta)^2+(tan alpha-tan beta)^2-sec^2 alpha" "...

    Text Solution

    |

  15. If p = sectheta - tan theta and q= "cosec"theta + cot theta, then what...

    Text Solution

    |

  16. What is the value of (sin34^@cos236^@-sin56^@sin124^@)/(cos28^@cos...

    Text Solution

    |

  17. tan54^@ can be expressed as

    Text Solution

    |

  18. Consider the following(for next three) items: If p=Xcostheta-Ysinth...

    Text Solution

    |

  19. Consider the following(for next three) items: If p=Xcostheta-Ysinth...

    Text Solution

    |

  20. Consider the following(for next three) items: If p=Xcostheta-Ysinth...

    Text Solution

    |