Question
If θ is an acute angle and sin θ + cosec θ = 2, then
the value of sin2 θ + cosec2 θ is:Solution
Given – sin + cseccθ = 2, let x = sin θ, then cosec θ =1/x ATQ- x+1/x =2  x²+1 = 2x x²-2x+1 0 (x-1)2 = 0 x-1 =0 x =1. Thus, sin θ = 1, which means θ = 90°. Now, Sin 2 θ = 15=1 Similarly, Cosec2 θ = 1 Therefore, Sin 2 θ + Cosec2 θ =1+1=2 So, the value is 2.
Which of the following organic compounds undergo nucleophilic substitution reaction most easily?
The process of converting a solid directly into its vapor is called:
What happens to a liquid, when the vapour pressure equals the atmospheric pressure?
In the synthesis of aspirin (acetylsalicylic acid) from salicylic acid, which reagent is used?
Which of the following statement is/are true?
I. Metal oxides are acidic in nature
II. Non-metallic oxides are basic in nature
Aromatic hydrocarbons contain at least how many benzene rings in their molecules?
Which gas is produced due to incomplete combustion of fuel?
_______ is a common name of ethanoic acid.
_____ is used for making chemical apparatus like beakers, flasks, etc.
The Polymerisation of which of the following is used in the manufacturing of polythene in industry?
Relevant for Exams:
