Possible Clues:

• Tips on where you will see astronomer and mathematician
• Mathematician replacing first item of geometer's equipment?
• Mathematician who introduced the function symbol f(x)
• Mathematician who smooths things in accounts
• Noted geometer
• Discoverer of the law of quadratic reciprocity
• Swiss mathematician the French overwhelmed with mounting regret
• Solver of the Königsberg bridge problem
• Prolific writer on calculus
• The French in their way backing Swiss mathematician